Will this lip clear my lower valance and splitter if I have aftermarket aero?

This lip bolts to factory mounting points and follows the OEM bumper profile. If you're running a custom splitter or lowered suspension, test-fit before final tightening to confirm clearance with your specific setup.

Do I need to prep and paint this before installing it?

It ships in matte black and can go on as-is. If you want a different finish or a gloss look, sand lightly with 220-grit, apply your primer and paint of choice, then install. The matte finish also works well for a stealth look if you leave it bare.

Are the bumper sensor holes already cut out?

Mounting method and sensor compatibility are not specified in the product data. Before committing to installation, verify your bumper sensor locations match this lip's design, or be prepared to carefully mark and drill cutouts if needed.