Hey Deuce106, were you ever able to figure out what it was? It sounds like I have the EXACT same problem as you. I have SR springs and the J&M pan hard bar as well, so I'm wondering maybe if the SR springs or bar have something to do with it? I'm bringing it in for the dealer to look at but I was hoping that I could get an answer from a forum, since I know some dealers are quick to write it off as aftemarket related and sometimes themselves can't give an accurate diagnosis. You are right, it does take the fun away from driving it. It sounds like there's a tire bouncing around loose in my trunk constantly. I don't really here it while cruising on the freeway, but on uneven streets it gets really bad at times. If I found out before you I'll let you know.