Maxton Design Rear Side Splitters for Audi A4 / A4 S line / S4 (B9)
Sharpen the rear profile of your A4 or S4 with these Maxton Design rear side splitters. Styled to complement OEM lines, they add a clean, OEM+ finish without looking overdone.
Designed using 3D scanning, they follow the bumper contours for a precise fit. Made from automotive-grade ABS plastic, they are light, durable and slightly flexible to help resist minor knocks. Finished in gloss black for an instant factory-style upgrade.
Fitment
Compatible with Audi A4 and S4 B9 models (Saloon and Avant) from 2016 to 2019, including S line. Fits only when paired with the matching Maxton Design rear diffuser/splitter system for the B9 A4/S4. Please use our vehicle lookup or check the Vehicle Fitment tab to confirm.
Whats in the box
- Rear side splitters – left and right
- Fitting kit
- Fitting manual
Finish and materials
Gloss black ABS plastic. No painting or extra prep required. A protective film is applied to prevent marks in transit.
Why this matters
These splitters tidy up the rear bumper area and visually lower the car. The result is a more purposeful stance that pairs well with other Maxton styling parts.
Installation and safety
We recommend professional installation unless you are confident following the manual. Test-fit before removing the protective film. Do not remove the holographic verification sticker if you may need to return the item. This product is TUV MATERIALGUTACHTEN certified.
Please ensure your vehicle matches the description above and images on our site before ordering. We are not responsible for incorrect installation or use.
Choosing a Kit
Our vehicle registration lookup system cannot detect factory trim level. It is important for customers to check the specification of their own vehicle against the product description, and if their vehicle has an existing sports trim level, body kit or factory enhancement that may cause it to look different from other similar models.
For example: Volkswagen R-Line, BMW M-Power/M-Pack, Audi S-Line, Ford ST-Line, Merc AMG-Line, Seat FR.
These kits will not fit models that don't meet these specifications.
Returns
Purchased the incorrect kit for your vehicle? Or not sure you like the surface finish when it arrives? No problem!
Maxton Design products are eligible for return if the product has not been fitted, drilled, modified or damaged in any other way and still has the protective factory film intact. Unfortunately, there are no exceptions, this applies to fully removed and partially removed films.
Products with a protective film in place are clearly marked with this sticker, if you believe there to be an issue with the product but you can't tell without removing the film, please contact our support team directly for assistance.

DO NOT REMOVE THE FACTORY FILM UNTIL YOU'VE LINED IT UP, AND YOU'RE READY TO FIT THE PART.
See our Terms & Conditions for more information.
Installation & Fitting
Instructions & Guides
Maxton Design provide either an online reference (below) or printed instructions with their products, we can't stress enough how important it is to follow these guidelines. Not only does this create a safe, aesthetically well fitted product, but it increases the longevity and lifespan of the kit.
Neither Progressive Parts nor Maxton Design will be able to provide and support or warranty for products fitted incorrectly. For example, front splitters require the front bumper to be removed, without doing so the bolts will be incorrectly positioned and may not be able to cope with the down-force exerted on it. Straying from the guidelines in this manner must be done so at the owners risk.
Fibreglass & "Non-Prepped" Products
By adding these products to your basket you are agreeing to the below statement.
All Maxton Design Fibreglass products including certain bumpers, spoilers, spoiler extensions and skirts will require “prep” before installing.
These are not a simple 'ready to fit' modification. In transit, the items may get chipped or marked and as such prior to painting it is important you understand that the parts may require filling, sanding and repairing (defined "prep") prior to paint being applied, which can be undertaken by any reputable body shop at minimal cost.
Return requests based on not anticipating the definition above are not accepted, please be aware you have agreed to this statement and the definition of “prep” work required prior to purchasing.
Product images shown for sale often indicate a finished product, the colour shown on the vehicle is for illustration purposes.
Fitting Manuals
Please note, Maxton Design products are only available for UK shipping.
Including Northern Ireland, Scottish Highlands and Channel Isles. Delivery fees apply.







