I am really surprised it didn't do anything! What brand did you use? Also, I noticed if you looked at the back panel, there are holes galore back there that would act like a amplifyer from the exhaust. So I covered the whole back area as well. I am going to double up on the trunk floor. Mine really isn't too bad if im driving around town from 0-50. When I get on it, it wakes up, but I like that! Haha. As soon as I get on the highway, it drones around 65-75mph. I have to stay right at 77-80 and its fine, but I am risking a ticket at that speed. If I could just kill the drone a little I would be happy.