I would recommend that you do not. I think if you did, you'd really regret it later on, plus they're a little expensive to make a mistake on. I just butt the leading front edge up against the front seat riser in the floor pan, as snug as it will go, then let the back trailing edge roll up on the floor pan riser underneath the leading edge of the rear seat. It doesn't look that bad IMHO, and it protects the carpet a bit better from a passengers heels, should you have any back there. They don't really shift at all in the wells either, where your feet are on top of them or otherwise.