Don't do it, man. The first time your trick pedal covers stick to the floor because the floor mat got pulled up too high...you'll thank me.
I once had a set: For 4 hours. In the middle of an autcross, at full throttle, the above-mentioned happened to me. Luckily, I was able to reach down and pull the floor mat back. Had I not, I'd have shot up an embankment at WOT at 40mph.
Plus...the pedal covers screw up one of the few things Nissan did perfectly on our cars: Pedal placement/size is as good as it gets.
its not because of the pedals that the mat got stuck. it happened to me a couple of times with the stock pedals. now ive put the mat clip back in and hooked it around the hole in the mat and it stays put.
and also, i dont think the stock setup is that good
stay away from Razo and other big pedal covers. The screws on the back of the pedal cover will stick to the skid pad on the carpet and/or possibly punch a hole in it. Momo pads are better cause the yare smaller. But IMHO they all suck and are mainly looks like cross drilled rotors.