Sharpen the Rear Corners—Without Replacing the Diffuser
Add a more planted, performance-inspired finish to your 2020–2024 Audi A4 or S4 B9.5. These model-specific carbon fiber deflectors mount over the outer sides of the factory rear diffuser for a focused OEM+ upgrade.
Two Carbon Fiber Side Deflectors
The set covers the outer left and right sections of the original rear diffuser, creating a wider-looking and more defined rear profile while retaining the factory diffuser.
Not a Complete Rear Diffuser
The factory diffuser, exhaust tips and center diffuser section shown in vehicle photos are not included.
Small Parts. Clear Visual Impact.
A targeted carbon upgrade for drivers who want a more aggressive rear view without committing to a full diffuser replacement.
Real Dry Carbon
3K carbon fiber construction delivers visible woven texture, low weight and a premium finish.
Model-Specific Shape
Contoured for the outer sections of the compatible B9.5 factory rear diffuser.
OEM+ Styling
Adds definition at both rear corners without overwhelming the original bumper design.
Simple Add-On Install
Pre-applied automotive adhesive tape means no drilling, cutting or diffuser removal.
Check Your Fitment Before Ordering
| Compatible Models | 2020–2024 Audi A4 / S4 B9.5 |
|---|---|
| Installation Area | Outer left and right sides of the factory rear diffuser |
| Required Configuration | OEM-style, unmodified rear diffuser matching the product photos |
| Not Listed | B9 pre-facelift models, RS4, Avant/wagon models and vehicles with aftermarket or modified diffusers |
Rear diffuser shapes can vary by trim and market. If you are unsure, email a clear rear-view photo and your model year to service@asigncar.com before ordering.
Choose Your Finish
Glossy Carbon
A deep, reflective clear-coated surface that emphasizes the 3K weave and pairs naturally with other gloss carbon exterior parts.
Matte Carbon
A low-reflection finish with a more understated, technical appearance.
Four-Step Tape-On Installation
Install only on a clean, dry surface and complete a full test fit before exposing the adhesive.
Test Fit
Confirm the left/right position, contour and edge alignment.
Clean
Remove dust, wax and oil, then allow the surface to dry completely.
Mount
Peel the tape backing gradually, align carefully and press into position.
Set
Apply firm, even pressure and avoid washing or high-pressure water for 72 hours.
Complete Pair
- 1 × left rear diffuser deflector
- 1 × right rear diffuser deflector
- Pre-applied automotive adhesive tape
At a Glance
- Material: real 3K dry carbon fiber
- Finish: glossy or matte
- Installation: tape-on add-on
- Approximate set weight: 300 g
Frequently Asked Questions
Is this a replacement rear diffuser?
No. This is a two-piece tape-on add-on for the outer sides of the original rear diffuser. The factory diffuser stays in place.
Does installation require drilling or bumper removal?
No. The deflectors install with pre-applied automotive adhesive tape. Drilling, cutting and diffuser removal are not required.
Will it fit an aftermarket rear diffuser?
Compatibility is based on the factory diffuser shape. Aftermarket and modified diffusers can have different contours, so please send us a rear-view photo before ordering.
Are both sides included?
Yes. One left deflector and one right deflector are included.
How should I care for the carbon finish?
Use a soft microfiber cloth and a pH-neutral automotive cleaner. Avoid abrasive compounds and aggressive polishing, especially on the matte finish.
Need a Fitment or Installation Check?
Send your model year and a clear rear-view photo to service@asigncar.com. The Asign support team can help confirm compatibility and placement.