Will this interfere with the front bumper at full compression or rough roads?

The C Speed profile is engineered to tuck under the OEM bumper, not extend beyond it. Run your vehicle over typical road surfaces before a track day to confirm clearance at your specific suspension height. If you've lowered the car significantly, verify ground clearance manually or at low speed first.

Does this mount with adhesive or do I need to drill through the bumper?

This lip bolts to factory mounting points — no adhesive, no drilling. Use the existing holes in your OEM bumper. Fasteners and their torque specs should match your vehicle's service manual; verify the bolt pattern before ordering if your bumper has been modified or replaced.

What finish prep does real carbon fiber need before install?

Carbon fiber comes ready to bolt on, but we recommend a protective clear coat over the weave to guard against UV fade and minor scuffs over time. Sand lightly and apply a quality automotive clear coat, or leave it raw if you prefer the natural finish. Either way, keep it clean and dry before mounting.