Sir Guy,
I agree, it sounds like the classic lower frame of rear window leak.
I had water in the trunk of my '90 560 SEC and after a lot of fiddling concluded the source of the water had to be the lower part of the rear window frame.
The repair itself is not too bad. Mine cost me $1,200 at a good body shop.
However, you have to remove the rear window in order to access the frame and it can easily crack or delaminate. Replacing the rear window is about $1,000.[xx(]
I was lucky and they managed to save my rear window. No guarantees though.
I agree, it sounds like the classic lower frame of rear window leak.
I had water in the trunk of my '90 560 SEC and after a lot of fiddling concluded the source of the water had to be the lower part of the rear window frame.
The repair itself is not too bad. Mine cost me $1,200 at a good body shop.
However, you have to remove the rear window in order to access the frame and it can easily crack or delaminate. Replacing the rear window is about $1,000.[xx(]
I was lucky and they managed to save my rear window. No guarantees though.