Will this diffuser scrape on steep driveways or inclines?

The diffuser extends below the rear bumper line, so approach angle matters on very steep inclines or unpaved surfaces. Measure your current ground clearance and compare to the diffuser profile before installation. If you frequently encounter steep approaches, test fitment with the vehicle on a known incline.

Is this functional downforce or purely cosmetic?

This is a Patriot style diffuser designed for visual impact and OEM-style appearance. Real aerodynamic benefit depends on vehicle speed and suspension tuning. Use it as a styling piece that complements the rear bumper; do not rely on it as a performance downforce tool.

What prep is needed before mounting?

Sand and prep the mounting surface on your rear bumper to ensure clean, bare plastic or composite. The diffuser mounts via fastener holes on the OEM bumper. Verify hole alignment with your current bumper before drilling or modifying. Once mounted, you can apply additional clear coat or protective coating to match your finish preference.