Will this diffuser scrape on steep driveways or inclines?

The Apex profile sits close to the bumper line without aggressive downward extension. Check your driveway angle and current bumper clearance before installation. If you regularly scrape your factory bumper, this diffuser will present similar risk — measure your approach angle to verify fit.

Does this diffuser add functional downforce or is it cosmetic?

This is a styled aero panel designed for visual impact. The Apex profile mimics performance diffuser lines but operates as an aesthetic enhancement rather than a functional aerodynamic device. Real downforce requires precise undertray geometry and tuning beyond this piece.

What surface prep is needed before painting?

Sand the surface with appropriate grit to smooth any texture, then apply your chosen primer and topcoat system. Work with your painter or refer to your paint manufacturer's prep guide for the best adhesion on FRP substrates.