Here's a couple more. I have not yet drilled holes in the seat backs (still debating whether or not to keep the liner). If you look at the "seatup.jpg" shot, the holes go on the top left and right of the seat backs. There is a healthy amount of velcro holding the liner on to the seatback - the pieces stay in place without the drilled fastener. If you leave the seats down, you probably don't need to drill any holes. If they are up all the time, I guess mazda wanted to ensure the liner is more firmly attached.