Do these need clear coat protection?

Yes. Carbon fiber benefits from a quality clear coat to protect the weave from UV exposure and maintain the gloss finish. Sand the surface lightly before applying your chosen clear coat system for best adhesion and longevity.

How do I seal the edges where the over fender meets the original panel?

Most builders use urethane trim seal or body seam sealer along the perimeter after final fitment. This prevents water intrusion and keeps the install looking factory-clean. Apply it after paint but before final assembly.

Will carbon fiber yellow or fade over time?

UV exposure can affect the resin finish, which is why clear coat is essential. With protective clear coat applied and reapplied as needed, the carbon weave stays vibrant. Without it, the resin can dull or yellow—so the prep and seal step really matters.