So I know there are a few threads floating around here about some of the annoying squeaks some our X's are blessed with and found an unlikely source of mine that I don't remember anyone mentioning. Been looking for this squeak for a long time now. Tried the whole hoodlatch thing with no success and dissected both of my seats and found nothing. Also retightened all my body mounts along with greasing them. One thing I found funny was this squeak happened the day after I got my 40 series Flowmaster installed. I even greased my muffler hangers with no luck. The other day I came home from work with it squeaking like a SOB. Was still squeaking after I put it into park so I put on the parking brake and threw myself under the X as fast as I could to catch that bastard of a squeak in action. It was my damn gas tank! The 2nd muffler hanger from the rear was vibrating the cross member it was connected too. This vibrating crossmember was sending a vibration to the gas tank making a crazy loud squeak that could be heard by people when you drive by. Metal and plastic rubbing together doesn't work. I loosened the rear gas tank strap, put a piece of rubber mat between the crossmember and tank, retightened the gas tank strap and pounded the **** out of the muffler shops hanger till there was virtually no stress on the rubber part of the hanger and voila no more squeak! Seems too much stress/weight on that certain hanger doesn't work well with the tank. Wondering if anyone with a stock muffler has this loud mystery squeak?