When I use to drive my car daily back in high school I had pacesetter LT's non-emission, off road y-pipe and an slp loudmouth. My car wasn't lowered and I had the occasional scrape when I went over speed bumps and stuff so I could definately see it being a problem with a car that is lowered 2 inches. As the for the coating, its not that great. I bought the coated ones, the coating is fine in the engine bay but after the driving the car a couple months and through the winter the coating by the collectors all flaked off. Which isn't a big deal I guess because you really just want the coating in the engine bay anyway to reduce heat.
Oh and as for sound. Yea its loud
, but I loved every second of it lol. Heres two videos, just to give you an idea.
Dyno Day Last Year.
1996 Chevrolet Camaro Z28 with bolt-ons Dynoing at TTP on NJFBOA Dyno Day makes 330 RWHP 343 RWTQ