I put the FRPP X Pipe on my 07 GT/CS but I had probs with the fit. I cut the downpipes exactly per the instructions but i couldn't slide the X Pipe over the ends because of the splay angle. I ended up cutting the downpipes 1- 1/2" shorter and butting up the x Pipe to the end of the downpipes. Now I have a slight rattle from the rear exhaust pipes on the underside of the body at certain revs. Anyone else had this problem?