THDP is a great piece. I've installed countless THDPs and never really have any problems. But every car sits different so somtimes you have to ding it here or there....but usually not. I've installed maybe 3 or 4 mease pipes...had problems with 2 or so on the fit, but it's an alright pipe too. I definatly like terry's pipe better.....his stainless 2 3/4 exhaust rocks too!
BTW, Terry has a downpipe just for the atr headers.....it comes out farther away from the exhaust housing before it goes down.