Do I need to drill new holes or modify the original fender?

No. These over fenders are designed to mount at factory attachment points. Verify your vehicle's existing fastener locations before installation — no cutting or drilling required on the original panel.

Should I sand and primer these before painting?

Yes. Sand the surface thoroughly and apply your chosen primer and color coat. FRP requires proper surface prep to ensure paint adhesion and longevity — treat prep as part of the installation process.

Will these affect my tire clearance or suspension geometry?

The 20mm extension adds visual width without raising the fender line significantly. If you're running a lifted suspension or aggressive wheel-and-tire combo, verify clearance before installation by checking your wheel diameter and offset against the new flare position.