I own a 2002 Boneville SSEI.
What would be the best
exhaust system for a
performance upgrade.
Thanks

Headers with downpipe, high flow cats, new mufflers.

Each thing you change will effect the tone. Series40 mufflers tend to have a nice note. But can cause a bit of a cabin drone. Don't remove the resonator, doing that tends to make the exhaust more raspy. I high flow cat will deepen the tone. headers will really wake up the sound. Beyond that, hi lift rockers, such at 1.9:1 or a cam will top it all off.

No offense to to Dan, but I hate the way the Flowmaster 40 sounds on our cars. Sure at idle it sounds great, but once you get above that it'* ricer.

The 80 and 40 are what most people use. A v6 simple has a raspy sound when you get a bit above idle. Some people have added a second resonator, and that tends to drop the rasp a bit.

Yeah, it'* hard to get away from the fact it'* a V6. That'* why I really like my Thrush mufflers. Nice deep tone at idle, no annoying rasp at throttle.

The Corsa exhaust kit for the sts sounds good on bonnies too
http://youtu.be/JXWf5RxEpt0
granted that car is not stock engine wise, it'* like I want my car to sound like eventually.

Is that the V6 or Northstar Caddy? Didn't listen.

its the v6 supercharged, he just bought the sts v8 exhaust kit I guess basically the same chassis and I think it'* still the 2.5" piping versus the 2.25" on the ssei I'm not sure though. Here'* the link to the system I found, a bit pricey:
http://www.summitracing.com/parts/CSE-14150/

Just listened. Don't like it. Sounds like its trying too hard if you know what I mean.