Will this diffuser scrape on driveways or steep inclines?

The Pro V profile adds minimal extension to the rear bumper line, so scrape risk is low under normal driving conditions. Check ground clearance at steep angles by comparing the diffuser tip to your factory bumper height before installation.

Is this functional downforce or purely cosmetic?

This is a styling diffuser designed for visual appeal and proportion, not aerodynamic downforce. It enhances the rear end's appearance without requiring specialized mounting or reinforcement.

What preparation does the FRP need before paint?

Sand the entire surface with appropriate grit to promote paint adhesion, then clean away dust thoroughly. Apply your chosen primer and paint system per manufacturer specs — the raw FRP condition means the gelcoat has been prepped for topcoat application.