Side Skirts
36 products
Carbon fiber side skirts and extensions for the BMW M3, M4 and M2, plus the X3M/X4M, M5, Audi RS3 and RS6 and Mercedes-AMG models. They come in two types: extensions that mount under the factory skirts, and full replacements that take the place of the M3/M4’s gloss-black skirt trim.
Unit 17’s own designs lead the G8X range: the V2 extensions and the extensions with a small winglet. We also design skirts for the G87 M2, the X3M/X4M and the RS3 facelift.
Side Skirts buying guide
Extensions or full replacement side skirts?
The factory side skirt on the G80 M3 and G82 M4 has a gloss-black trim piece that comes off. Full replacements swap that trim for carbon: the MP-style versions are 1:1 copies of the M Performance parts that use the OEM tabs and fixing points, with no drilling, and come with or without the rear winglet. Extensions keep your factory skirts and add a carbon blade underneath. The V2 is a bolt-on design in gloss or matte, and the small-winglet version mounts underneath with pre-drilled holes and self-tapping screws. Both are Unit 17 designs sold only here.
M3 and M4 skirts are not interchangeable
The replacements are sold as separate G80 M3 and G82 M4 listings, because each car takes its own part even when the style is the same. The V2 extensions ask you to pick G80, G82 or G83 at checkout. Shop by car under G80 M3 side skirts or G82/G83 M4 side skirts.
Other BMWs: check trim and body
- G87 M2: our side skirts with a winglet mount from underneath, and their stepped detail matches our front splitter.
- X3M/X4M: our extensions fit pre-LCI and LCI cars and stop just before the factory underglow light. The SQ-style skirts for the X3M LCI are coming soon, and the SOOQOO V2 also lists the non-M X3, X4 and iX3.
- M5 G90/G99: SQ-A (3M tape), SQ-B (factory mounting points) or MP style.
- F-series: the M Performance-style extensions fit the F30/F32 M Sport and F80 M3, not the M4, which has its own F82/F83 set. The G20 skirts are for M Sport cars only.
Audi and Mercedes-AMG
For the 2025-on RS3, our E1 Pro skirts fit the Sportback and sedan and are also sold with the S1 Pro lip, while the full sedan aero kit includes its own side skirt extensions. There are extensions for the RS6 Avant (C8), a pre-facelift W205 C63 skirt set, and extensions for the W205 and W204 C63 and CLA45. Most older listings come pre-drilled and say drilling is required, so book a body shop and test-fit first.
Frequently asked questions
Do side skirt extensions replace my factory side skirts?
No. Extensions attach under the factory skirts and leave them in place. Our small-winglet G8X set, for example, is an undermount extension, not the M Performance-style skirt with the large winglet. If you want the gloss-black trim gone, choose a full replacement set.
Will M4 side skirts fit my M3?
Not the full replacements. The G80 sedan and G82 coupe skirts are separate parts, so buy the listing for your car. The V2 extensions are sold for the G80 M3, G82 M4 and G83 convertible, and you choose your model at checkout.
Do I need to drill to fit carbon side skirts?
For the G8X full replacements, no: they use the OEM tabs and fixing points. The V2 extensions bolt on, and the M5 SQ-A skirts use 3M tape. The small-winglet extensions and many older listings use pre-drilled holes and self-tapping screws, which means drilling into the factory skirt.
Can I get matte or forged carbon side skirts?
The V2 extensions for the G80, G82 and G83 come in gloss or matte, chosen at checkout. The F80 M3 extensions are also sold in forged carbon. Most other sets are gloss, so check the finish line on each listing.
What makes the X3M/X4M side skirt extensions different?
They are a Unit 17 design, developed from 3D scans and tested at our New Jersey facility, and they fit pre-LCI and LCI X3M and X4M models. The blade runs forward from the rear and stops just before the factory underglow floor light, so the light still works.