-13%
Nissan Maxima Rear Diffuser Unpainted For 19-21 Nissan Maxima Stillen Nissan Maxima Rear Diffuser Unpainted For 19-21 Nissan Maxima Stillen Quick View

Stillen 2019-2021 Nissan Maxima Rear Diffuser [Unpainted] - KB12846

$376.54
$327.43
DJJX_KB12846
Diffusers Exterior Styling Stillen
Product Features Part Comes Pre-Installed with 3M Automotive Tape (Same as OEM uses) No Cutting or Modification to Bumper - Removable Polyurethane Construction Limited...
-15%
APR Performance Rear Diffuser Under Tray Only (AB-277018) APR Performance Rear Diffuser Under Tray Only (AB-277018) Quick View

APR Performance Rear Diffuser Under Tray Only (AB-277018)

$580.00
$493.00
BPDQ_AB-277018
APR Performance Diffusers Exterior Styling
Diffusers work in conjunction with other aerodynamic components of a car to help produce downforce. Because a car displaces air as it moves forward,...
-13%
Nissan Maxima Rear Diffuser Matted Black For 16-18 Nissan Maxima Stillen Nissan Maxima Rear Diffuser Matted Black For 16-18 Nissan Maxima Stillen Quick View

Stillen 2016-2018 Nissan Maxima Rear Diffuser [Matte Black] - KB12818MB

$364.58
$317.03
DJJX_KB12818MB
Diffusers Exterior Styling Stillen
Product Features Part Comes Pre-Installed with 3M Automotive Tape (Same as OEM uses) No Cutting or Modification to Bumper - Removable Painted Matte Black...
-13%
Nissan Altima Rear Diffuser Unpainted For 13-15 Nissan Altima Stillen Nissan Altima Rear Diffuser Unpainted For 13-15 Nissan Altima Stillen Quick View

Stillen 2013-2015 Nissan Altima Rear Diffuser [Unpainted] - KB13145

$348.71
$303.23
DJJX_KB13145
Diffusers Exterior Styling Stillen
Product Features Part Comes Pre-Installed with 3M Automotive Tape (Same as OEM uses) No Cutting or Modification to Bumper - Removable Polyurethane Construction -...
GReddy ROCKET BUNNY FD3S V2 REAR DIFFUSER (17040208) Quick View

GReddy ROCKET BUNNY FD3S V2 REAR DIFFUSER (17040208)

$510.00
BHXF_17040208
Diffusers Exterior Styling Greddy
The Rocket Bunny Aero V2 Rear Diffuser for the RX-7 FD3S platform adds a super aggressive new look, all the way around your vehicle....
GReddy ROCKET BUNNY FRS V1 REAR DIFUSER (17010215) GReddy ROCKET BUNNY FRS V1 REAR DIFUSER (17010215) Quick View

GReddy ROCKET BUNNY FRS V1 REAR DIFUSER (17010215)

$560.00
BHXF_17010215
Diffusers Exterior Styling Greddy
Kei Miura's design have gained global acclaim for the trend-setting style that drives automotive enthusiast, to demand authentic Rocket Bunny / Pandem aero kits....
GReddy ROCKET BUNNY FRS REAR DIFFUSER LIGHT (17010217) Quick View

GReddy ROCKET BUNNY FRS REAR DIFFUSER LIGHT (17010217)

$65.00
BHXF_17010217
Diffusers Exterior Styling Greddy
This is the optional reverse light that goes in the center of the Rocket Bunny rear diffuser for the Scion FR-S / Subaru BRZ...
GReddy PANDEM RX8 REAR DIFFUSER (17040409) GReddy PANDEM RX8 REAR DIFFUSER (17040409) Quick View

GReddy PANDEM RX8 REAR DIFFUSER (17040409)

$530.00
BHXF_17040409
Diffusers Exterior Styling Greddy
The Pandem V1 Rear Diffuser for the RX-8 platform adds a super aggressive new look, all the way around your vehicle. Each Pandem kit...
GReddy ROCKET BUNNY R35 V2 REAR DIFFUSER (FRP) (17020644) Quick View

GReddy ROCKET BUNNY R35 V2 REAR DIFFUSER (FRP) (17020644)

$1,980.00
BHXF_17020644
Diffusers Exterior Styling Greddy
The Rocket Bunny Aero V2 Rear Diffuser for the Nissan R35 platform adds a super aggressive new look, all the way around your vehicle....
GReddy PANDEM R35 REAR CENTER DIFFUSER (17020611) Quick View

GReddy PANDEM R35 REAR CENTER DIFFUSER (17020611)

$1,540.00
BHXF_17020611
Diffusers Exterior Styling Greddy
The Pandem R35 Rear Center Diffuser for the Nissan R35 platform adds a super aggressive new look, all the way around your vehicle. Each...
GReddy PANDEM R35 REAR SIDE DIFFUSER (DC) (17020610) Quick View

GReddy PANDEM R35 REAR SIDE DIFFUSER (DC) (17020610)

$2,420.00
BHXF_17020610
Diffusers Exterior Styling Greddy
The Pandem R35 Rear Side Diffuser-Dry Carbon for the Nissan R35 platform adds a super aggressive new look, all the way around your vehicle....
GReddy PANDEM R35 REAR SIDE DIFFUSER (FRP) (17020609) Quick View

GReddy PANDEM R35 REAR SIDE DIFFUSER (FRP) (17020609)

$1,540.00
BHXF_17020609
Diffusers Exterior Styling Greddy
The Pandem R35 Rear Side Diffuser-FRP for the Nissan R35 platform adds a super aggressive new look, all the way around your vehicle. Each...
GReddy ROCKET BUNNY RPS13 380 Aero REAR DIFFUSER (17020386) GReddy ROCKET BUNNY RPS13 380 Aero REAR DIFFUSER (17020386) Quick View

GReddy ROCKET BUNNY RPS13 380 Aero REAR DIFFUSER (17020386)

$560.00
BHXF_17020386
Diffusers Exterior Styling Greddy
The Rocket Bunny 380 Rear Diffuser for the Nissan S13 platform adds a super aggressive new look, all the way around your vehicle. Each...
GReddy ROCKET BUNNY MIATA ND REAR DIFFUSER (17040234) Quick View

GReddy ROCKET BUNNY MIATA ND REAR DIFFUSER (17040234)

$725.00
BHXF_17040234
Diffusers Exterior Styling Greddy
The Rocket Bunny V1 Rear Diffuser for the Miata ND platform adds a super aggressive new look, all the way around your vehicle. Each...
GReddy ROCKET BUNNY Z33 REAR DIFFUSER (17020355) Quick View

GReddy ROCKET BUNNY Z33 REAR DIFFUSER (17020355)

$880.00
BHXF_17020355
Diffusers Exterior Styling Greddy
The Rocket Bunny V2 Rear Diffuser for the Nissan 350Z platform adds a super aggressive new look, all the way around your vehicle. Each...
GReddy PANDEM RX-7 BOSS REAR DIFFUER (17040309) GReddy PANDEM RX-7 BOSS REAR DIFFUER (17040309) Quick View

GReddy PANDEM RX-7 BOSS REAR DIFFUER (17040309)

$495.00
BHXF_17040309
Diffusers Exterior Styling Greddy
The Pandem Boss Rear Diffuser for the RX-7 FD3S platform adds a super aggressive new look, all the way around your vehicle. Each Pandem...
GReddy PANDEM RX-7 FC3S REAR DIFFUSER (17040335) Quick View

GReddy PANDEM RX-7 FC3S REAR DIFFUSER (17040335)

$510.00
BHXF_17040335
Diffusers Exterior Styling Greddy
The Pandem V1 Rear Diffuser for the RX-7 FC3S platform adds a super aggressive new look, all the way around your vehicle. Each Pandem...
GReddy ROCKET BUNNY RC-F REAR UNDER DIFFUSER (17010254) Quick View

GReddy ROCKET BUNNY RC-F REAR UNDER DIFFUSER (17010254)

$1,150.00
BHXF_17010254
Diffusers Exterior Styling Greddy
Kei Miura's design have gained global acclaim for the trend-setting style that drives automotive enthusiast, to demand authentic Rocket Bunny / Pandem aero kits....
GReddy ROCKET BUNNY 86/FRS/BRZ V2 REAR DIFFUSER (17010233) GReddy ROCKET BUNNY 86/FRS/BRZ V2 REAR DIFFUSER (17010233) Quick View

GReddy ROCKET BUNNY 86/FRS/BRZ V2 REAR DIFFUSER (17010233)

$560.00
BHXF_17010233
Diffusers Exterior Styling Greddy
Kei Miura's design have gained global acclaim for the trend-setting style that drives automotive enthusiast, to demand authentic Rocket Bunny / Pandem aero kits....
GReddy PANDEM E92 REAR DIFFUSER (17090256) Quick View

GReddy PANDEM E92 REAR DIFFUSER (17090256)

$485.00
BHXF_17090256
Diffusers Exterior Styling Greddy
The Pandem V1 Rear Diffuser for the BMW E92 platform adds a super aggressive new look, all the way around your vehicle. Each Pandem...
GReddy PANDEM 86/FRS/BRZ V3 REAR DIFFUSER (17010276) Quick View

GReddy PANDEM 86/FRS/BRZ V3 REAR DIFFUSER (17010276)

$460.00
BHXF_17010276
Diffusers Exterior Styling Greddy
Each Pandem kit is manufactured using a CAD design, which allows for the highest quality, and the cleanest OEM fitments for each specific vehicle....
GReddy ROCKET BUNNY RC REAR DIFFUSER (17010263) Quick View

GReddy ROCKET BUNNY RC REAR DIFFUSER (17010263)

$1,150.00
BHXF_17010263
Diffusers Exterior Styling Greddy
Kei Miura's design have gained global acclaim for the trend-setting style that drives automotive enthusiast, to demand authentic Rocket Bunny / Pandem aero kits....
GReddy ROCKET BUNNY S15 REAR DIFFUSER (17020264) Quick View

GReddy ROCKET BUNNY S15 REAR DIFFUSER (17020264)

$560.00
BHXF_17020264
Diffusers Exterior Styling Greddy
The Rocket Bunny V2 Rear Diffuser for the Nissan S15 platform adds a super aggressive new look, all the way around your vehicle. Each...
GReddy ROCKET BUNNY S14 V2 Boss Aero REAR DIFFUSER (17020309) Quick View

GReddy ROCKET BUNNY S14 V2 Boss Aero REAR DIFFUSER (17020309)

$490.00
BHXF_17020309
Diffusers Exterior Styling Greddy
The Rocket Bunny V2 Boss Aero Rear DIffuser for the Nissan S14 platform adds a super aggressive new look, all the way around your...
GReddy PANDEM 180SX V3 REAR DIFFUSER PLATES (66920371) GReddy PANDEM 180SX V3 REAR DIFFUSER PLATES (66920371) Quick View

GReddy PANDEM 180SX V3 REAR DIFFUSER PLATES (66920371)

$65.00
BHXF_66920371
Diffusers Exterior Styling Greddy
PANDEM 180SX V3 REAR DIFFUSER PLATES.Each Pandem kit is manufactured using a CAD design, which allows for the highest quality, and the cleanest OEM...
GReddy PANDEM GR86 REAR DIFFUSER (66910876) GReddy PANDEM GR86 REAR DIFFUSER (66910876) Quick View

GReddy PANDEM GR86 REAR DIFFUSER (66910876)

$600.00
BHXF_66910876
Diffusers Exterior Styling Greddy
PANDEM GR86 REAR DIFFUSER.Each Pandem kit is manufactured using a CAD design, which allows for the highest quality, and the cleanest OEM fitments for...
-5%
GReddy AERO REAR UNDER SPOILER FRS/BRZ (17010205) Quick View

GReddy AERO REAR UNDER SPOILER FRS/BRZ (17010205)

$480.00
$456.00
BHXF_17010205
Diffusers Exterior Styling Greddy
The GRACER Rear Lip adds a level of aerodynamics to a often overlooked area. Rear aerodynamics has an impact on traction, handling and overall...
-15%
Seibon Carbon fiber rear diffuser cover for 2013-2016 Scion FRS / 2013-2017 Subaru BRZ (RDC1213SCNFR Quick View

Seibon Carbon fiber rear diffuser cover for 2013-2016 Scion FRS / 2013-2017 Subaru BRZ (RDC1213SCNFR

$840.00
$714.00
HGQB_RDC1213SCNFRS
Diffusers Exterior Styling Seibon Carbon
Seibon creates performance oriented carbon fiber body panels that save weight, add style and are durable enough to hold up under grueling racing conditions....
-15%
Seibon Carbon fiber rear diffuser for 2016 Ford Focus RS (RD16FDFO-OE) Quick View

Seibon Carbon fiber rear diffuser for 2016 Ford Focus RS (RD16FDFO-OE)

$1,100.00
$935.00
HGQB_RD16FDFO-OE
Diffusers Exterior Styling Seibon Carbon
Seibon creates performance oriented carbon fiber body panels that save weight, add style and are durable enough to hold up under grueling racing conditions....
-15%
Seibon OEM-style carbon fiber rear diffuser for 2008-2012 Mitsubishi Lancer EVO X (RD0809MITEVOX-OE) Quick View

Seibon OEM-style carbon fiber rear diffuser for 2008-2012 Mitsubishi Lancer EVO X (RD0809MITEVOX-OE)

$880.00
$748.00
HGQB_RD0809MITEVOX-OE
Diffusers Exterior Styling Seibon Carbon
Seibon creates performance oriented carbon fiber body panels that save weight, add style and are durable enough to hold up under grueling racing conditions....
-15%
Seibon Carbon fiber rear diffuser for 2006-2007 Subaru Impreza/WRX (RD0607SBIMP) Quick View

Seibon Carbon fiber rear diffuser for 2006-2007 Subaru Impreza/WRX (RD0607SBIMP)

$770.00
$654.50
HGQB_RD0607SBIMP
Diffusers Exterior Styling Seibon Carbon
Seibon creates performance oriented carbon fiber body panels that save weight, add style and are durable enough to hold up under grueling racing conditions....
-15%
Seibon Carbon fiber rear diffuser for 2001-2005 BMW E46 M3 (RD0105BMWE46M3) Quick View

Seibon Carbon fiber rear diffuser for 2001-2005 BMW E46 M3 (RD0105BMWE46M3)

$770.00
$654.50
HGQB_RD0105BMWE46M3
Diffusers Exterior Styling Seibon Carbon
Seibon creates performance oriented carbon fiber body panels that save weight, add style and are durable enough to hold up under grueling racing conditions....
-15%
Seibon OEM-style carbon fiber rear under spoiler for 2009-2010 Nissan GTR (RL0910NSGTR-OE) Quick View

Seibon OEM-style carbon fiber rear under spoiler for 2009-2010 Nissan GTR (RL0910NSGTR-OE)

$1,760.00
$1,496.00
HGQB_RL0910NSGTR-OE
Diffusers Exterior Styling Seibon Carbon
Seibon creates performance oriented carbon fiber body panels that save weight, add style and are durable enough to hold up under grueling racing conditions....
-15%
Seibon Carbon Fiber Rear Diffuser for Toyota Supra 20+ (RD20TYSUP) Seibon Carbon Fiber Rear Diffuser for Toyota Supra 20+ (RD20TYSUP) Quick View

Seibon Carbon Fiber Rear Diffuser for Toyota Supra 20+ (RD20TYSUP)

$1,320.00
$1,122.00
HGQB_RD20TYSUP
Diffusers Exterior Styling Seibon Carbon
Seibon creates performance oriented carbon fiber body panels that save weight, add style and are durable enough to hold up under grueling racing conditions....
-15%
Seibon Gloss Carbon Fiber Rear Diffuser for 2015-2020 Subaru WRX(RD18SBIMP) Seibon Gloss Carbon Fiber Rear Diffuser for 2015-2020 Subaru WRX(RD18SBIMP) Quick View

Seibon Gloss Carbon Fiber Rear Diffuser for 2015-2020 Subaru WRX(RD18SBIMP)

$1,980.00
$1,683.00
HGQB_RD18SBIMP
Diffusers Exterior Styling Seibon Carbon
Rear Diffuser by Seibon.Give your car a high-tech aerodynamic look with this carbon fiber rear diffuser.A rear diffuser can redirect airflow coming from underneath...
Seibon Carbon Fiber Rear Diffuser for 2017-2020 Tesla 3(774-T14MD3RL) Seibon Carbon Fiber Rear Diffuser for 2017-2020 Tesla 3(774-T14MD3RL) Quick View

Seibon Carbon Fiber Rear Diffuser for 2017-2020 Tesla 3(774-T14MD3RL)

$1,182.50
HGQB_774-T14MD3RL
Diffusers Exterior Styling Seibon Carbon
Seibon 17-20 Tesla Model 3 Carbon Fiber Rear DiffuserFeatures: High quality at an affordable price Expertly made from premium materials Built to match your...
Items 1 to 36 of 152 total

When constructing a race car, no matter whether it's a purpose built track machine or a modified production vehicle, car builders try to achieve an aerodynamic balance between drag and downforce. Minimizing drag reduces the air resistance encountered by the car, allowing it to go faster. Downforce is necessary so the tires stay firmly planted on the track surface for optimal power delivery, steering and braking. Diffusers, air dams and side skirts combine to increase down force on race cars. If you want to make your machine look like it's ready for the track, check out our selection of diffusers.

Although some body mods increase drag to create downforce, this tradeoff is necessary for overall vehicle performance. However, there are component choices a builder can make that maximize downforce without creating excessive drag. Such is the case with a rear diffuser. When combined with an air dam and side skirts, a rear diffuser functions to increase the velocity of the air flowing underneath the car and increase downforce and traction at the tires.

According to Bernoulli's Principle, when the velocity of air increases, its pressure decreases. This means that the air pressure above the car is greater, and this greater pressure exerted downward provides the necessary downforce. Although components like rear wings can also be used to provide downforce, they create much more aerodynamic drag while doing so than a rear diffuser. The diffuser provides the space for the high velocity, low pressure air flow to decelerate and expand at the rear of the vehicle, creating a pressure differential and more downforce. Diffusers also typically have dividers that allow the air flow to transition to the airstream at the back of the car without creating turbulence and drag.

Of course, the above description applies mainly to a car constructed expressly for racing. Such cars usually have smoother undercarriages to facilitate the increased air flow velocity, and they are driven at much higher speeds than are allowable on the highway, so the average street driven car will not realize all of a diffuser's benefits. But we know that the visual appeal of a custom rear diffuser and aerodynamic body components in general is just as, if not more important to street driven car owners than functionality, which is why we have the extensive selection of diffusers you see on the page before you.

We offer rear diffusers for most popular cars in materials including carbon fiber, aluminum, urethane, fiberglass, fiberglass composite, ABS plastic and stainless steel. Depending on application, some are designed to be a fully custom addition, while others are replacements for the OE diffuser but are manufactured in an upgraded material like carbon fiber. Some applications are designed to be used with specific exhaust systems. And because each of our rear diffusers is carefully designed for a specific model, regardless of your choice you can count on ease of fitment, and an appearance that will command attention and perfectly complement your vehicle's styling.

Your cart

×