I just took 1999 E320 4M wagon to the dealership to have the motor mounts replaced, but the service writer told me that it would be a risky job due to a cracked exhaust flange. On the paperwork, the dealership wrote, "TRIED TO REPLACE MOTOR MOUNTS, FOUND LH EXH PIPE COLLAR AT CONNECTION POINT BETWEEN F PIPE AND MUFFLER ID BROKEN, HOLDING NOW BUT IF REMOVED MAY NOT REINSTALL. NWP." Apparently, fixing the exhaust flange requires replacement of the muffler which I did not agree to. What needs to be done to repair the exhaust (without muffler replacement) so I can do the motor mount job? Thanks in advance!