The Airdam on the Laurel is coroplast, and is attached to the plastic lower valence using self-drilling screws and some penny washers. The outer sections that curve around the bumper ends are zip tied to the middle section. It is braced by coroplast triangles on the rear side, also zip tied in place.
Took about an hour to fit, with most of the time spent bracing it from the back to stop it folding under in the wind.
Before:
After (showing zip ties + screws)
Finished product.
