Will this diffuser scrape on driveway inclines or steep approach angles?

Three-piece design sits closer to the OEM bumper line than single-piece alternatives, minimizing overhang. Check your vehicle's current ground clearance at the rear bumper and compare to your typical driveway geometry before installation.

Does this diffuser provide functional downforce or is it cosmetic?

MTS style diffusers are primarily cosmetic — they enhance the rear appearance and visual depth without aerodynamic function. For measurable downforce, you'd need a full aero package with front, side, and rear elements working together.

What should I use to prep the FRP before painting?

Sand the surface with appropriate grit to scuff and open the pores, then wipe clean of all dust. Refer to your chosen paint system's prep guidelines — primer type and application method vary by brand. Test fit first to ensure all three pieces align properly before any finishing work.