Will the lip sit flush with the bumper or does it extend beyond the OEM lower edge?

The wave-style design follows the factory bumper contour. Before installation, test-fit the lip against your bumper to confirm alignment with the lower edge and side transitions. Any gaps can be addressed with shims or epoxy during final fitment.

Should I use adhesive or drill mounting holes?

Both methods work with FRP. Adhesive is cleaner and reversible; drilling offers permanent security. Ensure the bumper surface is clean, dry, and lightly sanded before applying either method. For adhesive installation, use a flexible automotive-grade construction adhesive rated for plastic-to-plastic bonding.

Will this interfere with the trunk seal or air dam at speed?

The wave profile is designed to integrate with factory airflow paths and should not contact the trunk seal or undercarriage components. Check clearance at the side edges where the lip meets the OEM bumper corners — minor trimming may be needed if your bumper has underseal or trim clips in those zones.