Soonercruiser has the Xenon side skirts. Looks great! But, they are primarily held on the sides with 3M tape. There are a few screws in the wheel wells only.
Mine were coming loose after inside of one year since the body shop installed and did the custom paint. So, I had to pull the side skirts out as best I could; pull off the old tape that was coming loose; apply adhesion promoter; and reapply the 3M tape. 2 more years down the road now, an no adhesion problems.
(And I'm a mechanical & body rookie)