Hello Digesters: I have a 98 M3 and am thinking about a tri-flow exhaust. Is this a good system? Are there any better ones? Do you get the same HP increase from any exhaust system, some claim 5-6 hp and some claim 20HP. I do not want a lot of noise or vibrations in the car? thanks bob ------------------------------ End of bmw-digest V9 #504 *************************