Side Skirts Guide: Do They Help, Which Material, and How to Fit Them

Side skirts are one of the simplest aero upgrades you can make. They fill the gap between the front and rear wheels, give the car a lower stance and protect the sills from curbs, cones and track debris.

Do Side Skirts Actually Do Anything?

On a street car, side skirts are mostly about looks and protection. At track speeds they help by limiting how much high-pressure air spills under the car from the sides, which keeps the underbody airflow cleaner. The effect is small on its own, but it adds up when you pair skirts with a front lip and rear diffuser.

Side Skirt Materials Compared

• ABS plastic: flexes on contact and pops back. The best pick for low cars and drift builds.
• Polypropylene (PP): similar flex to ABS, often used for OEM-style replacement skirts.
• FRP (fiberglass): cheap and easy to repair with resin, but cracks on hard hits.
• Carbon fiber: the lightest and best looking, and the most expensive to replace.

Full Skirts vs Skirt Extensions

Full replacement skirts swap the factory rocker panel. Skirt extensions bolt or rivet under the factory skirt, which is easier, cheaper and keeps the original panel intact. Universal sectional extensions can be cut to length for almost any car, like these Miata NA-ND sectional side skirt extensions. Chassis-specific options such as the BRZ, FR-S and 86 side skirt extensions fit without trimming.

How to Fit Side Skirts

1. Clean the rocker panel and test-fit the skirt with tape before drilling anything.
2. Check ground clearance with the car at ride height; aim for at least a finger's width more clearance than your front lip.
3. Use rivnuts or bolts at the ends and 3M tape along the length, so the skirt can flex without tearing out.
4. On drift cars, leave a breakaway point so a hard hit pulls the skirt off rather than damaging the body.

Browse all side skirts by car, or see this range of side skirts and extensions.

Shop Aero by Car

• Nissan 350Z and 370Z body kits and aero
• Mazda Miata MX-5 body kits and aero
• GR86, BRZ and FR-S body kits and aero
• Ford Mustang body kits and aero
• BMW E36 body kits and BMW E46 body kits

FAQ

Are side skirts worth it?

For looks and sill protection, yes. For lap time, they help most as part of a full aero package.

Will side skirts scrape?

On lowered cars, sometimes. ABS and PP skirts tolerate scraping far better than fiberglass or carbon.