Will this diffuser scrape on steep driveways or speed bumps?

The MKS profile sits close to the bumper line with minimal extension below the factory perimeter. Review your vehicle's approach angle and driveway slope before final installation. A test fit with the panel loosely mounted will show ground clearance in your specific setup.

What prep work does FRP need before painting?

Sand the surface with appropriate grit to promote adhesion, then wipe clean and dry. Use a flexible primer and paint system designed for plastic substrates. Your local automotive paint supplier can recommend products matched to your topcoat choice.

Does this bolt directly to the factory rear bumper, or do I need custom brackets?

The diffuser uses factory mounting points on the rear bumper assembly. Verify bolt hole alignment with your bumper's existing structure before drilling or fastening. Standard hand tools and fasteners are sufficient for installation.