Will this diffuser scrape on driveway inclines or speed bumps?

The Vantix profile sits close to the factory bumper line, so clearance mirrors your stock setup. If your vehicle bottoms out on steep driveways now, this diffuser won't change that. Verify ground clearance with your current suspension height before ordering.

Does this add functional downforce or is it cosmetic?

This is a styling diffuser designed to enhance the rear end's visual proportion. For measurable aerodynamic benefit, you'd need a much larger, track-focused setup. This diffuser excels at filling the rear bumper cavity and sharpening the design line.

What prep work is needed before paint?

Sand the entire surface with fine-grit paper to scuff the primer coating and promote adhesion. Clean thoroughly to remove dust and oils. Once prepped, apply your primer or base coat per your paint system's instructions. Most shops recommend 2–3 light coats for even coverage.