The Borla is a bolt on, but the old exhaust has to be cut off behind the cat. The kit includes a templete to locate the second hole in the bumper skirt. It's not exactly symmetrical side to side, so hesitate to cut the hole before you get the kit. Also be aware that the pipes move front to back and, more importantly, side to side as they heat up and cool down. Smartly, the tips are double walled so if they can touch the skirt for a short time without damage. I think adding these lost the power I'd gained with the CAI and headers. They are also a little boomy at 3k rpm. But they look way too NICE to worry about any of that.