81 240d manual tranny center support failure question

[Cobb2]

I was doing 70 on i95 north and about one exit I heard a hand full of change hit the road. I thought that was rather strange as I wouldnt think you could hear that from the engine and road noise. Next exit, bang, bang, bang, something hit the bottom of my car and caused everything inside to bounce that was in the floor area, seats, dashboard and part of the key cylinder feel out of the dash board. The rear wheels were skipping and I drove it sideways across three lanes to the side of the road. I put it in nutral and turned off the engine.

I thought a wheel came off. Looked around car, saw all wheels were on. Went down the road on til I hit 40mph, same thing, bang, bang, bang. I pulled over and thought maybe a wheel is loose. All wheels were tight, tried it again.

Got to 35mph, same noise. Slowed it to 20 and it went away.

Long story short its at a benz dealer awaiting service. I was told last time that the center support bearing was damaged when it was installed last time and it was 364 to get it done again and 2 hours labor.

Last time this was done you just heard the drive shaft rub the bottom of the car. Sounded like a cat purring, not banging like.

Think something else went wrong? How much think repairing it would be?