Thanks! Yes GM mats. Snaps were 12 bucks for a kit on amazon. Just got stainless snaps made for a boat cover. I did learn a lot along the way. I was trying to punch a hole in the mat while it was in place then see that mark in the carpet. If I could redo the process, I'd install the snaps in the mat in the proper locations then lay the mat in the truck, push down on the snap to make a ring in the carpet and just screw the stud into the middle of the circle. I'm really happy with everything except the holes I made in the wrong spot on the one seat back...