Shop Our Clearance Sale - Up To 80% Off FREE SHIPPING on Orders $49+ *exclusions apply

Menu

Call Us330-331-2003 ChatLive Chat Text Us!
0 Shopping Cart
Your Vehicle

No Vehicle selected
Please select your vehicle below.

    • Audi
    • BMW
    • Mercedes Benz
    • MINI
    • Porsche
    • Volkswagen

Saved Vehicles

My Vehicles
You currently have no stored vehicles.

Recent Vehicles

Recent Vehicles Manage Vehicles

You currently have no recent vehicles.

We'll automatically keep fully selected vehicles here for your convenience.

Call Us330-331-2003 ChatLive Chat Text Us!
Track My Order View Order History Submit a Return Contact Us Wholesale Information Lifetime Replacement Returns and Warranty Information
0
Call Us330-331-2003 ChatLive Chat Text Us!
Track My Order View Order History Submit a Return Contact Us Wholesale Information Lifetime Replacement Returns and Warranty Information
Cancel
0
Sales & Specials
Enter Your Vehicle
garage-red
Your Vehicle Please tap 'Select' to pick a vehicle
Your Vehicle Please tap 'Select' to pick a vehicle
Select

Audi S4 Rear Bumper Diffusers

Sort By
Filter By
Return to Top

Audi B8.5 S4 / A4 S-Line Rear Diffuser - Gloss Black

ES#4147363 - 028807ecs01KT - Audi B8.5 S4 / A4 S-Line Rear Diffuser - Gloss Black - Add some aggressive styling to your Audi! - ECS - Audi

Add some aggressive styling to your Audi! 10X Entries Into Our F80 M3 Sweepstakes

Fits facelift B8.5 (2013+) models only

Brand:
ECS - Corporate Logo
ES#:
4147363
Mfg#:
028807ECS01KT
In Stock
ON SALE! SAVE 20%
$407.99

This product was last offered at the strikethrough price on
06-13-2026

$326.39 USD
Free Shipping
This product is lifetime replacement eligible Lifetime Replacement

Audi B9 S4 Rear Diffuser - Gloss Black

ES#4056580 - 006077LA01 - Audi B9 S4 Rear Diffuser - Gloss Black - Add some aggressive styling to your Audi! - ECS - Audi

Add some aggressive styling to your Audi! 10X Entries Into Our F80 M3 Sweepstakes

Fits pre-facelift models (up to 2019) without integrated tips in the rear valance

Brand:
ECS - Corporate Logo
ES#:
4056580
Mfg#:
006077LA01
In Stock
ON SALE! SAVE 25%
$420.99

This product was last offered at the strikethrough price on
06-13-2026

$315.99 USD
Free Shipping
This product is lifetime replacement eligible Lifetime Replacement

Audi B8 S4 / A4 S-Line Rear Diffuser - Gloss Black

ES#4033487 - 028808ECS01 - Audi B8 S4 / A4 S-Line Rear Diffuser - Gloss Black - Add some aggressive styling to your Audi! - ECS - Audi

Add some aggressive styling to your Audi! 10X Entries Into Our F80 M3 Sweepstakes

Fits pre-facelift B8 models only

Brand:
ECS - Corporate Logo
ES#:
4033487
Mfg#:
028808ECS01
In Stock
ON SALE! SAVE 25%
$420.99

This product was last offered at the strikethrough price on
06-13-2026

$315.99 USD
Free Shipping
This product is lifetime replacement eligible Lifetime Replacement

Audi B8.5 S4 / A4 S-Line Carbon Fiber Rear Diffuser

ES#3085916 - 018359ECS01A - Audi B8.5 S4 / A4 S-Line Carbon Fiber Rear Diffuser - Hand-laid carbon fiber to upgrade your exterior styling - ECS - Audi

Hand-laid carbon fiber to upgrade your exterior styling 10X Entries Into Our F80 M3 Sweepstakes

From the 2013 model year

Brand:
ECS - Corporate Logo
ES#:
3085916
Mfg#:
018359ECS01A
In Stock
ON SALE! SAVE 10%
$1019.99

This product was last offered at the strikethrough price on
06-13-2026

$917.99 USD
Free Shipping
This product is lifetime replacement eligible Lifetime Replacement

Audi B8.5 S4 Facelift Rear Diffuser & Trunk Spoiler

ES#4751213 - 026861ECS01EBKT - Audi B8.5 S4 Facelift Rear Diffuser & Trunk Spoiler - Add some aggressive styling to your Audi! - Enthusiast Bundles - Audi

Add some aggressive styling to your Audi! Don't See A Bundle You Want - Give Us A Call Or Chat - We Will Make One!
Fits facelift B8.5 (2013+) models only

Brand:
Enthusiast Bundles - Corporate Logo
ES#:
4751213
Mfg#:
026861ECS01EBKT
In Stock
ON SALE! SAVE 49%
$785.48

This product was last offered at the strikethrough price on
05-05-2026

$399.99 USD
Free Shipping
This product is lifetime replacement eligible Lifetime Replacement

Audi B9 S4 Carbon Fiber Rear Diffuser

ES#3247439 - 023797ECS01 - Audi B9 S4 Carbon Fiber Rear Diffuser - Hand-laid carbon fiber to upgrade your exterior styling - ECS - Audi

Hand-laid carbon fiber to upgrade your exterior styling 10X Entries Into Our F80 M3 Sweepstakes

Fits pre-facelift models (up to 2019) without integrated tips in the rear valance

Brand:
ECS - Corporate Logo
ES#:
3247439
Mfg#:
023797ECS01
In Stock
ON SALE! SAVE 42%
$1029.99

This product was last offered at the strikethrough price on
05-02-2026

$599.99 USD
Free Shipping
This product is lifetime replacement eligible Lifetime Replacement

Audi B8.5 S4 / A4 S-Line Forged Carbon Fiber Rear Diffuser

ES#4490851 - 018359ECS01-02 - Audi B8.5 S4 / A4 S-Line Forged Carbon Fiber Rear Diffuser - Hand-laid chopped carbon fiber to upgrade your exterior styling - ECS - Audi

Hand-laid chopped carbon fiber to upgrade your exterior styling 10X Entries Into Our F80 M3 Sweepstakes

From the 2013 model year

Brand:
ECS - Corporate Logo
ES#:
4490851
Mfg#:
018359ECS01-02
In Stock
ON SALE! SAVE 30%
$998.99

This product was last offered at the strikethrough price on
05-02-2026

$699.99 USD
Free Shipping
This product is lifetime replacement eligible Lifetime Replacement

Carbon Fiber Rear Diffuser - Audi B8 A4/S4 Pre-facelift

ES#3200799 - 021532ECS01A - Carbon Fiber Rear Diffuser - Audi B8 A4/S4 Pre-facelift - Hand-laid carbon fiber to upgrade your exterior styling - ECS - Audi

Hand-laid carbon fiber to upgrade your exterior styling 10X Entries Into Our F80 M3 Sweepstakes

Up to the 2012 model year

Brand:
ECS - Corporate Logo
ES#:
3200799
Mfg#:
021532ECS01A
In Stock
ON SALE! SAVE 30%
$999.99

This product was last offered at the strikethrough price on
05-02-2026

$699.99 USD
Free Shipping
This product is lifetime replacement eligible Lifetime Replacement

Audi B8.5 S4 / A4 S-Line Rear Bumper Side Splitters - Gloss Black

ES#4044452 - 024846ecs01KT1 - Audi B8.5 S4 / A4 S-Line Rear Bumper Side Splitters - Gloss Black - Spice up the exterior of your Audi with gloss black spats! - ECS - Audi

Spice up the exterior of your Audi with gloss black spats! 10X Entries Into Our F80 M3 Sweepstakes

Fits 2013+ A4 S-Line and S4 rear bumpers

Brand:
ECS - Corporate Logo
ES#:
4044452
Mfg#:
024846ECS01KT1
In Stock
ON SALE! SAVE 25%
$139.99

This product was last offered at the strikethrough price on
06-13-2026

$104.99 USD
Free Shipping
This product is lifetime replacement eligible Lifetime Replacement

Audi B9 S4 / A4 S-Line Rear Bumper Side Splitters - Gloss Black

ES#4164511 - 004751la01 - Audi B9 S4 / A4 S-Line Rear Bumper Side Splitters - Gloss Black - Spice up the exterior of your Audi with gloss black spats! - ECS - Audi

Spice up the exterior of your Audi with gloss black spats! 10X Entries Into Our F80 M3 Sweepstakes

Fits pre-facelift models up to 2019 model year

Brand:
ECS - Corporate Logo
ES#:
4164511
Mfg#:
004751LA01
In Stock
ON SALE! SAVE 25%
$133.99

This product was last offered at the strikethrough price on
06-13-2026

$100.49 USD
Free Shipping
This product is lifetime replacement eligible Lifetime Replacement

Audi B8 S4 Pre-facelift Rear Diffuser & Trunk Spoiler

ES#4751215 - 026861ECS01EB2KT - Audi B8 S4 Pre-facelift Rear Diffuser & Trunk Spoiler - Add some aggressive styling to your Audi! - Enthusiast Bundles - Audi

Add some aggressive styling to your Audi! Don't See A Bundle You Want - Give Us A Call Or Chat - We Will Make One!
Fits pre-facelift B8 models only

Brand:
Enthusiast Bundles - Corporate Logo
ES#:
4751215
Mfg#:
026861ECS01EB2KT
In Stock
ON SALE! SAVE 35%
$733.99

This product was last offered at the strikethrough price on
05-05-2026

$478.97 USD
Free Shipping
This product is lifetime replacement eligible Lifetime Replacement

Audi B9 S4 Pre-facelift Rear Diffuser & Trunk Spoiler

ES#4751275 - 028801ECS01EBKT - Audi B9 S4 Pre-facelift Rear Diffuser & Trunk Spoiler - Add some aggressive styling to your Audi! - Enthusiast Bundles - Audi

Add some aggressive styling to your Audi! Don't See A Bundle You Want - Give Us A Call Or Chat - We Will Make One!
Fits pre-facelift models (up to 2019) without integrated tips in the rear valance

Brand:
Enthusiast Bundles - Corporate Logo
ES#:
4751275
Mfg#:
028801ECS01EBKT
In Stock
ON SALE! SAVE 34%
$696.26

This product was last offered at the strikethrough price on
05-05-2026

$458.51 USD
Free Shipping
This product is lifetime replacement eligible Lifetime Replacement

Carbon Fiber Rear Valance w/Rear Splitter

ES#3142795 - AS410-CFRVP - Carbon Fiber Rear Valance w/Rear Splitter - Delivers an unmatched combination of aggressiveness and luxury elegance - Deval - Audi

Delivers an unmatched combination of aggressiveness and luxury elegance

Brand:
Deval - Corporate Logo
ES#:
3142795
Mfg#:
AS410-CFRVP
Special Order: No Guaranteed ETA
$1000.00 USD
Free Shipping
This product is lifetime replacement eligible Lifetime Replacement

Carbon Fiber Rear Diffuser

ES#4000981 - D38234 - Carbon Fiber Rear Diffuser - Designed and manufactured to improve performance and everyday drivability - Deval - Audi

Designed and manufactured to improve performance and everyday drivability

Brand:
Deval - Corporate Logo
ES#:
4000981
Mfg#:
D38234
Special Order: No Guaranteed ETA
$890.00 USD
This product is lifetime replacement eligible Lifetime Replacement

Carbon Fiber Rear Diffuser

ES#3142811 - D28244 - Carbon Fiber Rear Diffuser - Delivers an unmatched combination of aggressiveness and luxury elegance - Deval - Audi

Delivers an unmatched combination of aggressiveness and luxury elegance

Brand:
Deval - Corporate Logo
ES#:
3142811
Mfg#:
D28244
Special Order: No Guaranteed ETA
$850.00 USD
This product is lifetime replacement eligible Lifetime Replacement

Audi B8 S4 Pre-facelift Gloss Black Rear Diffuser & Trunk Spoiler

ES#4750959 - 028808ECSEBKT - Audi B8 S4 Pre-facelift Gloss Black Rear Diffuser & Trunk Spoiler - Add some aggressive styling to your Audi! - Enthusiast Bundles - Audi

Add some aggressive styling to your Audi! Don't See A Bundle You Want - Give Us A Call Or Chat - We Will Make One!

Brand:
Enthusiast Bundles - Corporate Logo
ES#:
4750959
Mfg#:
028808ECSEBKT
In Stock
ON SALE! SAVE 24%
$733.99

This product was last offered at the strikethrough price on
05-05-2026

$560.69 USD
Free Shipping
This product is lifetime replacement eligible Lifetime Replacement

Let us help you find the parts that fit your Audi

ECS Tuning is not affiliated with any automobile manufacturers.
Manufacturer names and/or part numbers are used only for identification purposes.

Terms of Use Privacy Policy Your Privacy Choices Cookie Policy ECS Tuning is part of Enthusiast Auto Holdings