Will this scrape on steep driveways or inclines?

The wave profile extends minimally below the OEM bumper line. Check the clearance at your driveway's steepest angle before final installation. Most owners find standard driving clearance unaffected; verify your specific setup before committing fasteners.

Is this functional downforce or purely cosmetic?

This is a styling diffuser. It adds visual definition to the rear end. For aerodynamic performance, it works as part of a complete rear package; on its own, treat it as a design accent rather than a performance modifier.

What prep and finish should I apply before installation?

Sand the mounting surface and any contact points lightly to ensure clean fitment. The carbon fiber comes unfinished — apply your chosen clear coat or protective finish before or after install depending on your access and preference. A UV-protective clear coat extends the weave appearance and resists oxidation.