Will this diffuser scrape on steep driveways or inclines?

The diffuser extends below the rear bumper, so approach angles on steep inclines or over-aggressive driveways will determine clearance. Inspect your typical driving routes and measure ground clearance at your steepest approach before installation. Soft body contact with low obstacles is less catastrophic than hard impacts, but awareness prevents unnecessary contact.

Is this diffuser functional or cosmetic?

This is a styling diffuser. It delivers visual aggression and rear-deck presence; aerodynamic benefit at street speeds is minimal. If you're seeking functional downforce and stability at high speed, consult aero specialists for validated packages. This part excels as a aggressive aesthetic enhancement.

What prep is required before painting?

Sand the primer surface with appropriate abrasive media and clean thoroughly before applying basecoat and clear. Ensure all edges and crevices are free of dust and debris. Follow your chosen paint system's surface preparation guidelines for best adhesion and finish quality.