Will this scrape on driveways or steep inclines?

The diffuser profile is designed to sit near the rear bumper line without significant extension. Test clearance in your driveway before committing; garage angles and suspension ride height vary by setup. If you run lowered suspension, verify ground clearance at your favorite approach angle.

Is the downforce functional or cosmetic?

This is a functional downforce diffuser. The geometry is engineered to manage rear airflow separation and reduce lift under acceleration, most noticeable at highway speeds and on track. It's not a massive aero overhaul, but it works.

What finish should I apply?

Carbon fiber arrives unfinished and ready for prep. Sand and prep the surface, then apply your choice of clear coat or paint system. A quality UV-protective clear coat is recommended to preserve the weave and prevent oxidation over time.