Will this diffuser scrape on steep driveways or inclines?

Diffusers mount low on the bumper and can contact ground on sharp angles. Test your approach and departure angles at home before final installation. If clearance is tight, consider an adjustable mounting approach or verify exact bumper geometry before committing to fasteners.

Is this purely cosmetic or does it serve a functional purpose?

This is a cosmetic piece that adds visual style to the rear end. It follows King styling cues and does not generate downforce. Its primary role is aesthetic enhancement to the bumper profile.

What prep work is needed before painting?

Sand and prep the surface before applying your chosen finish. The FRP arrives in raw FRP condition, meaning it's clean and ready to accept primer and topcoat. Follow your paint supplier's surface preparation guidelines for best adhesion and durability.