Will this interfere with my trunk seal or bumper alignment?

No—this lip mounts beneath the bumper cover using factory points, so it doesn't alter how the bumper seats or how your trunk closes. Clearance was designed with stock fitment in mind.

Does this affect brake light visibility or cutouts?

The lip is positioned low and forward; it does not block or interfere with brake light cutouts. Your existing lights remain fully visible and functional.

Is this stable at highway speeds?

Yes. At factory ride height, this under-bumper design produces minimal lift and won't cause vibration or instability on the highway. If you've lowered the car significantly, verify your preferred ground clearance before finalizing fitment.