Do these ducts require cutouts in my bumper?

Yes. These are designed as bolt-on or adhesive-mount ducts for an existing bumper. You'll need to reference your specific bumper's vent opening location and size before installation. Measure and test-fit before committing to any permanent modifications.

Can I install these before painting, or should I finish them first?

Either approach works. Many builders prefer to paint the ducts off-vehicle for cleaner coverage and easier masking. Sand and prep the surface before applying your chosen primer and topcoat. Installation can happen once the finish is fully cured.

Will FRP hold up to heat and UV exposure on the front bumper?

FRP is naturally UV-resistant and performs well under typical street use and weather exposure. A quality topcoat will extend durability further. Avoid prolonged direct sunlight storage without cover to minimize any potential long-term fade.