Does this bumper have fog light cutouts or sensor holes?

Check your vehicle's OEM bumper for existing fog light and sensor locations. You can route or drill to match, or integrate aftermarket fog housings as desired. The base panel ships solid and ready for your custom configuration.

Do I need to modify my lower valance or undertray to fit this bumper?

This bumper uses factory mounting points. Review how the new Trackstar profile sits relative to your existing undertray before final installation. Minor trimming of plastic tabs may be needed depending on your specific setup.

What should I do to prepare this for paint?

Sand and prep the surface with appropriate grit before applying your chosen base coat and clear. Follow your paint supplier's recommendations for surface preparation and primer compatibility with FRP.