Do I need to modify the body to install these?

No. These over fenders bolt directly to factory mounting points without cutting, drilling, or welding. Verify that your existing fender mounting hardware is clean and tight before installation.

What finish should I apply before installation?

Sand and prep the surface with your preferred grit, then apply your chosen primer and paint system. Installation can happen before or after finishing — bolt it first if you prefer to paint the assembly in place.

Will the extended width affect tire clearance or suspension geometry?

These over fenders extend the body profile only; they do not alter suspension or tire fitment. Inspect your tire clearance after installation to ensure no contact with the new fender line, especially if you run wider or lower than stock.