Will this diffuser clear the exhaust tip and bumper on stock suspension?

Yes. The VT profile is designed to sit flush with the rear bumper at stock ride height. If you've lowered the vehicle significantly or modified the exhaust outlet position, verify tip clearance before final fitment.

Does this diffuser have functional vanes or is it cosmetic?

This is a cosmetic styling piece. It complements the rear bumper line and adds visual depth but does not generate downforce or alter aerodynamic flow. It's built for clean OEM-style appearance.

Will the diffuser scrape on steep inclines or driveways?

The VT design hugs the bumper profile and sits at stock height, so ground clearance matches your vehicle's bumper. Verify your current bumper height against driveways or ramps before installation to ensure your setup won't have clearance issues with any rear bumper accessory.