Will this scrape on steep driveways or inclines?

The Zamba profile adds modest extension at the rear bumper line. Verify ground clearance against your vehicle's current suspension height and any driveway approach angles before final installation. If you've lowered the vehicle significantly, test fitment carefully.

Is this diffuser functional downforce or cosmetic?

The Zamba geometry is designed with downforce-focused fin blade configuration. Real aerodynamic benefit depends on highway speed and how air flows under your specific vehicle setup—the diffuser optimizes that path, but it works best as part of a complete aero package rather than standalone.

What finish should I apply to the carbon?

Your choice. UV-protective clear coat preserves the weave and prevents oxidation. You can also wet-sand and paint it to match body color, or leave it raw carbon for maximum visual contrast. Sand and prep the surface before applying your chosen finish.