I just ordered mine and can't wait to put them on! I read through this whole thread though..and now I'm worried about droning in the cabin with the windows up. I can't stand that...hopefully it won't be unbearable.
For anyone who is looking to get them at a good price..they're for sale at Amazon for $332!!
http://www.amazon.com/Flowmaster-817.../dp/B003Z4FETU