Is this only happening on the 350s? I have a 2008 250. I don't want my baby's mufflers floppin around.

It's been discussed before. They bounce because of the rubber hangers. Some ppl used zip ties around the hangers. In addition, if you look closely the left exhaust tip is lower than the right. Using the zip ties serve two purposes - even the gap and control the bouncing by lifting up the exhaust a little bit. That's what I did and now the exhaust tips are level and with very little play or bounce.