Will the diffuser scrape on inclines or driveway aprons?

The diffuser adds minimal extension below the factory bumper line. Verify ground clearance at your vehicle's approach angle before final installation. Most OEM bumper-mounted accessories have similar rake to the stock setup.

Do I need to drill new holes, or does it use existing bumper mounting points?

This diffuser is designed to mount at factory bumper attachment locations. No new drilling required — confirm alignment with your vehicle's OEM bumper mounting brackets before fastening.

Is this purely cosmetic, or does it provide any functional benefit?

The diffuser is primarily cosmetic, adding visual aggression and style to the rear end. The integrated channels are styled for appearance rather than aerodynamic effect at street speeds.