My exhaust pipe on the left side (drivers side in the rear part of the car only) rattles when I start it up in cold outside temps. If I put my foot on the exhaust tip while the cars running the rattle ceases. I had the car up 2 months ago by Midas as they could locate the source or find any faulty heatshields. Can this be a bracket or hanger that's gone bad? The rattling goes away once the car reaches normal opp. temp. Any ideas? Looking for a underside pic of this exhaust area so I can put this annoyance to rest!