No one thinks about it until hearing the anguished shriek of metal on pavement coming from beneath them. My 450SL used the rubber donuts, it ate them every 60 days or so (but the PO had modified the exhaust from stock). I just gave up and bought metal hangers. Never had another problem.

The 126, as Mike says, has greatly improved rubber hangers.

__________________
Tjohn

82 300 SD
77 450 SL (gone)