Sorry to hear this lads .We have 2 members in the uk forum with the same problem .And i am looking for someone to do the same repairs to the subfram mountings for them .Not an easy job as the subframe needs removing to get in to weld the sections in. looked at the one sub frome and it was coverd with underseal from Mercedes ,it was so hard and brittle and looked a lot like fibreglass . It had split over time to let the damp and water get inside to rot away out of sight. Good luck and hope you both get this sorted out asap .