Do I need to prep the FRP before painting?

Yes. Sand the surface with appropriate grit to open the surface, then wipe clean of dust. This ensures paint adhesion. After sanding, apply your chosen primer and topcoat according to the paint manufacturer's instructions.

Will these fenders fit with my factory lug bolts and mounting hardware?

These over fenders integrate with factory mounting points. Verify your vehicle's OEM bolt locations match the fender hole pattern before final installation. You may need fasteners matching your existing hardware specification.

What's the best way to seal the seams between the over fender and OEM body?

After installation and paint, apply a flexible body sealer or trim-matched caulk along the seams to prevent water intrusion and maintain a finished appearance. This step prevents debris accumulation and extends the panel's service life.