I had an exhaust issue only yesterday. Had a half completed exhaust system under the car including a $200 oval shaped stainless muffler before the diff. Only needed the pipe over the diff and out the back finished. Put the car on the trailer to take it to the exhaust shop for finishing and on the 16km trip into town the $200 muffler decided it was time to part company. I remember that I never tightened the clamp bolt. Bugger..!!
$345 later I have a new stainless muffler under the car...and the exhaust is finished.