Maxton Design Rear Side Flaps V2 for BMW M135i (F70)
Add a sharper rear profile to your M135i. These rear side flaps extend the line of the bumper and splitter, giving a clean, motorsport-inspired look without hurting everyday use.
Fitment
Designed for the BMW M135i F70, 2024 onwards. Fits only with Maxton Design Rear Side Diffusers V2 (BM170MCNC-RSD2) installed. Use our vehicle lookup or see the Vehicle Fitment tab to confirm compatibility.
Material and build
Made from ABS plastic used by many car makers for exterior parts. It is light, tough, and resistant to weather, UV, and heat. Supplied in durable black, ready to fit or paint if required.
Why it matters
Crisp, defined edges at the rear improve the cars stance and visual width. Any aerodynamic effect is mild, but the added stability at speed can be noticeable on motorways.
Installation and safety
Direct fit using the included hardware. Test fit first, clean mounting surfaces, and tighten fixings evenly. Check fasteners after the first few drives. Do not block sensors or reflectors.
Whats included
- Rear side flaps (pair)
- Fitting kit
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.







