The Tri-mil is a good system; I believe it's fairly non-restrictive as it's 1-1/2" and it gives out a throaty sound very much reminiscent of the old 356's. I just installed one in my car and it sounds great. One caveat though, I've noticed that the version sold by Vintage Speedsters is modified to fit their Speedster replicas; Jjr sold me a new unit he bought after finding out it wouldn't clear the back apron on his CMC. Since he didn't want to cut it I ended up buying it from him. YOu should first check with them to make sure it fits your make of car. If by any chance you buy the regular production model available for Bugs, Ghias, Buses, etc. it's not guaranteed that it will fit either although I've heard the ones for Speedsters are the same as for Buses. I've noticed that on mine the tailpipes are sort of facing a little down and not totally horizontally with the car.