ground effects
There are 4 (2 per side) bracket pieces that are rivited on the front bumper. The front ground effects sit on those then through the holes they use the plastic locking screws into the bumper... atleast for my RS 4th gen styled ones. 3 locking screws on the bottom, 2 in the wheel well... on each front ground effect. I havent looked at the side or rear yet.
Its possible they rivet those...

