Will this interfere with my trunk seal or undercarriage at speed?

No. This front lip mounts to your lower bumper area and does not extend into trunk or undercarriage zones. Verify that your OEM bumper sits flush before installation to avoid any contact with the lip edge during normal driving or parking over obstacles.

Should I use adhesive or drill through the mounting points?

Use the factory bolt holes for a secure, reusable connection. Drilling additional holes is not necessary — align the lip with your OEM anchor points and fastener pattern, then bolt down. This approach is stronger than adhesive alone and lets you remove the lip later if needed.

What prep work does the surface need before paint?

Sand and smooth the surface with appropriate abrasive, then wipe down and apply your chosen primer and topcoat. Work in a clean, dust-free environment to avoid trapped particles. The FRP surface will accept standard automotive primers and paints.