Home » Audi A4 B9 S Line / S4 Sedan Carbon Fiber Rear Bumper Diffuser 2017–2019

Audi A4 B9 S Line / S4 Sedan Carbon Fiber Rear Bumper Diffuser 2017–2019

Upgrade the rear-end appearance of your 2017–2019 Audi A4 B9 S Line / S4 Sedan with this carbon fiber rear bumper diffuser. Designed as a replacement-style rear lower valance upgrade, this diffuser adds a sharper, more aggressive rear profile while keeping a clean gloss carbon fiber finish.

This ML-HZJ011-2 rear diffuser is designed for selected Audi A4 B9 S Line and S4 Sedan models with the matching rear bumper style. It is a strong fit for customers looking for an Audi A4 B9 S Line carbon fiber rear diffuser, Audi S4 B9 carbon fiber rear diffuser, or Audi A4 S4 B9 rear bumper diffuser.

Fitment

Make Audi
Model A4 S Line / S4
Chassis B9 / Typ 8W
Year 2017–2019
Body Style Sedan
Product Position Rear bumper lower diffuser / rear valance area
Not Fit Audi A4 Base non-S Line rear bumper, Avant / Wagon, RS4, A5 / S5 / RS5, B8 / B8.5, 2020+ B9.5 models, or aftermarket rear bumpers unless confirmed by photos

Important: Please compare your rear bumper style with our product photos before ordering. If you are unsure about fitment, please send us your vehicle year, trim and rear bumper photos through our contact us page.

Sensor Notice: If your vehicle has a rear kick sensor, rear sensor cover, or sensor-related trunk opening function, please confirm with us before ordering. Some sensor functions may be affected after installing an aftermarket rear diffuser.

Product Specifications

  • SKU: ML-HZJ011-2
  • Material: Real carbon fiber
  • Carbon Weave: 3K twill carbon fiber
  • Finish: Gloss carbon fiber finish with UV-protected clear coating
  • Style: Replacement-style rear bumper diffuser / rear valance upgrade
  • Design Detail: Red center light detail
  • Installation Method: Factory screw locations may be reused; professional installation recommended
  • Package Includes: 1 rear bumper diffuser

Key Features

  • Designed for selected 2017–2019 Audi A4 B9 S Line / S4 Sedan models
  • Gloss 3K twill carbon fiber finish for a cleaner rear-end upgrade
  • Rear diffuser design helps create a sportier and more aggressive rear bumper appearance
  • Red center light detail adds a distinctive rear styling element
  • Replacement-style structure designed for the rear lower bumper area
  • Quality checked before shipment
  • Protected export carton packaging
  • Professional installation is recommended

Installation Notes

This rear bumper diffuser is a replacement-style exterior part. Factory screw locations may be reused during installation, but final mounting may depend on bumper condition, vehicle configuration and installer adjustment.

Test fit the diffuser before final installation. Make sure the rear bumper area is clean and dry, and confirm the alignment around the exhaust openings, side edges and center section before securing the product. Professional installation is recommended.

Before Ordering

This product is designed for selected Audi A4 B9 S Line and S4 Sedan rear bumper styles. It is not designed for A4 Base non-S Line bumpers, Avant / Wagon models, RS4, A5 / S5 / RS5, B8 / B8.5, 2020+ B9.5 models, or aftermarket rear bumpers unless confirmed by our team.

Explore More Audi A4 / S4 Carbon Fiber Upgrades

Looking for more exterior upgrades for the same platform? Browse our Audi A4/S4 carbon fiber parts collection for related front lips, rear diffusers, spoilers, mirror covers and exterior upgrades.

You can also explore more Audi carbon fiber parts from AHACARBON, or return to the AHACARBON carbon fiber car parts homepage.

FAQ

Does this fit Audi A4 Base models?

No. This rear diffuser is designed for selected Audi A4 B9 S Line and S4 Sedan rear bumper styles. It is not designed for A4 Base non-S Line rear bumpers.

Does this fit Audi RS4?

No. This product is not designed for Audi RS4 models. Please check RS4-specific rear diffuser products instead.

Does this fit Audi A5, S5 or RS5?

No. This rear diffuser is not designed for Audi A5, S5 or RS5 models.

Will this affect the rear sensor or kick sensor?

Sensor function may be affected depending on vehicle configuration. If your vehicle has a rear kick sensor or sensor-related trunk opening function, please contact us with photos before ordering.

How is this rear diffuser installed?

This is a replacement-style rear diffuser. Factory screw locations may be reused, but test fitting and professional installation are recommended for proper alignment.

Audi A4 B9 S Line S4 carbon fiber rear diffuser installed rear view
2017-2019 Audi A4 S4 B9 rear bumper diffuser installed comparison
Audi A4 B9 S Line S4 carbon fiber rear diffuser full view
Audi S4 B9 carbon fiber rear bumper diffuser angled product view
Audi A4 B9 S Line rear diffuser front and back product view
Audi S4 A4 Sline B9 Sedan 2017-2019 Rear Bumper Diffuser Carbon Fiber-Ahacarbon
Audi A4 S4 B9 rear diffuser red center light rear view
Audi A4 B9 carbon fiber rear diffuser red center light detail
Audi A4 S4 B9 carbon fiber rear diffuser side angle view
Audi A4 B9 S Line rear diffuser side outlet detail
Audi A4 S4 B9 carbon fiber rear diffuser product features
Audi S4 B9 rear diffuser gloss 3K twill carbon fiber detail
Audi A4 B9 S Line S4 carbon fiber rear diffuser installed rear view
2017-2019 Audi A4 S4 B9 rear bumper diffuser installed comparison
Audi A4 B9 S Line S4 carbon fiber rear diffuser full view
Audi S4 B9 carbon fiber rear bumper diffuser angled product view
Audi A4 B9 S Line rear diffuser front and back product view
Audi S4 A4 Sline B9 Sedan 2017-2019 Rear Bumper Diffuser Carbon Fiber-Ahacarbon
Audi A4 S4 B9 rear diffuser red center light rear view
Audi A4 B9 carbon fiber rear diffuser red center light detail
Audi A4 S4 B9 carbon fiber rear diffuser side angle view
Audi A4 B9 S Line rear diffuser side outlet detail
Audi A4 S4 B9 carbon fiber rear diffuser product features
Audi S4 B9 rear diffuser gloss 3K twill carbon fiber detail

Audi A4 B9 S Line / S4 Sedan Carbon Fiber Rear Bumper Diffuser 2017–2019

In stock
$ 704.99 USD
-10% $ 783.32 USD $ 704.99 USD

✔ 30-Day Hassle-Free Returns
✔ Factory Direct Pricing (No Middleman)
✔ Professional Installation & After-Sale Support

Audi A4 B9 S Line / S4 Sedan Carbon Fiber Rear Bumper Diffuser 2017–2019

Upgrade the rear-end appearance of your 2017–2019 Audi A4 B9 S Line / S4 Sedan with this carbon fiber rear bumper diffuser. Designed as a replacement-style rear lower valance upgrade, this diffuser adds a sharper, more aggressive rear profile while keeping a clean gloss carbon fiber finish.

This ML-HZJ011-2 rear diffuser is designed for selected Audi A4 B9 S Line and S4 Sedan models with the matching rear bumper style. It is a strong fit for customers looking for an Audi A4 B9 S Line carbon fiber rear diffuser, Audi S4 B9 carbon fiber rear diffuser, or Audi A4 S4 B9 rear bumper diffuser.

Fitment

Make Audi
Model A4 S Line / S4
Chassis B9 / Typ 8W
Year 2017–2019
Body Style Sedan
Product Position Rear bumper lower diffuser / rear valance area
Not Fit Audi A4 Base non-S Line rear bumper, Avant / Wagon, RS4, A5 / S5 / RS5, B8 / B8.5, 2020+ B9.5 models, or aftermarket rear bumpers unless confirmed by photos

Important: Please compare your rear bumper style with our product photos before ordering. If you are unsure about fitment, please send us your vehicle year, trim and rear bumper photos through our contact us page.

Sensor Notice: If your vehicle has a rear kick sensor, rear sensor cover, or sensor-related trunk opening function, please confirm with us before ordering. Some sensor functions may be affected after installing an aftermarket rear diffuser.

Product Specifications

  • SKU: ML-HZJ011-2
  • Material: Real carbon fiber
  • Carbon Weave: 3K twill carbon fiber
  • Finish: Gloss carbon fiber finish with UV-protected clear coating
  • Style: Replacement-style rear bumper diffuser / rear valance upgrade
  • Design Detail: Red center light detail
  • Installation Method: Factory screw locations may be reused; professional installation recommended
  • Package Includes: 1 rear bumper diffuser

Key Features

  • Designed for selected 2017–2019 Audi A4 B9 S Line / S4 Sedan models
  • Gloss 3K twill carbon fiber finish for a cleaner rear-end upgrade
  • Rear diffuser design helps create a sportier and more aggressive rear bumper appearance
  • Red center light detail adds a distinctive rear styling element
  • Replacement-style structure designed for the rear lower bumper area
  • Quality checked before shipment
  • Protected export carton packaging
  • Professional installation is recommended

Installation Notes

This rear bumper diffuser is a replacement-style exterior part. Factory screw locations may be reused during installation, but final mounting may depend on bumper condition, vehicle configuration and installer adjustment.

Test fit the diffuser before final installation. Make sure the rear bumper area is clean and dry, and confirm the alignment around the exhaust openings, side edges and center section before securing the product. Professional installation is recommended.

Before Ordering

This product is designed for selected Audi A4 B9 S Line and S4 Sedan rear bumper styles. It is not designed for A4 Base non-S Line bumpers, Avant / Wagon models, RS4, A5 / S5 / RS5, B8 / B8.5, 2020+ B9.5 models, or aftermarket rear bumpers unless confirmed by our team.

Explore More Audi A4 / S4 Carbon Fiber Upgrades

Looking for more exterior upgrades for the same platform? Browse our Audi A4/S4 carbon fiber parts collection for related front lips, rear diffusers, spoilers, mirror covers and exterior upgrades.

You can also explore more Audi carbon fiber parts from AHACARBON, or return to the AHACARBON carbon fiber car parts homepage.

FAQ

Does this fit Audi A4 Base models?

No. This rear diffuser is designed for selected Audi A4 B9 S Line and S4 Sedan rear bumper styles. It is not designed for A4 Base non-S Line rear bumpers.

Does this fit Audi RS4?

No. This product is not designed for Audi RS4 models. Please check RS4-specific rear diffuser products instead.

Does this fit Audi A5, S5 or RS5?

No. This rear diffuser is not designed for Audi A5, S5 or RS5 models.

Will this affect the rear sensor or kick sensor?

Sensor function may be affected depending on vehicle configuration. If your vehicle has a rear kick sensor or sensor-related trunk opening function, please contact us with photos before ordering.

How is this rear diffuser installed?

This is a replacement-style rear diffuser. Factory screw locations may be reused, but test fitting and professional installation are recommended for proper alignment.