Will this fit the factory fog light cutouts without modification?

The Markham bumper has its own fog light openings as part of the design. Compare the hole diameter and position against your current setup before installation. If your vehicle has OEM sensors in the lower bumper area, verify their location matches the new panel's cutout geometry.

Can I install this without modifying the lower valance or air dam?

The Markham style includes an integrated air dam that sits lower than stock. Check clearance with your current lower valance trim, splitter, or diffuser if installed. You may need to modify or remove existing components to avoid interference.

What's the best way to prep this before painting?

Sand the surface thoroughly and clean off any dust or mold release residue. Apply your chosen primer and topcoat according to your paint manufacturer's specs. Since it ships raw FRP, you're starting from a clean substrate — proper surface prep is key to finish quality.