i have the 40 seriese flows. they sound great. you said that your friend has them also but you dont like the noise inside the car? depends on where the exhaust ends at (correct me if im wrong) mine comes out the back in 2 1/2 pipes and i dont hear much sound inside unless im on the freeway going 70 or so at 4,000RPM's. My opinion would to go with the 40 seriese and just get a big stereo system and drownd out the sound like i do..
