So I recently bought a 2011 Mustang GT and the first thing I did (without really reading into it enough) was bought and installed a pair of Flowmaster Hushpowers. After about a month I really can't stand the constant drone around 2,000 rpm (and neither can my neighbors car, sets off the alarm every morning right when the needle hits 2k rpm). After reading through numerous threads and forums, seems like I should've gone with the GT500's. Is there anyway to get rid or minimize this drone at 2k??? I removed the gray foam from the inside of the firewall (didn't help). I'm thinking of maybe some additional resonators? (I don't want to restrict any HP) Or will it just be cheaper to buy the GT500's and try to sell these Hushpowers... What do you think???