Quite an interesting thread, this one, since acquiring my 90, I have carried out a full seam and door rubbers check, using TIGER SEAL, and running seal along all roof seams, ( older type three bar roof on my 90 ), then all sides and rear seams, then all front bulkhead area seams. Note, this tiger seal is pretty good stuff.
after the above, I have found very minor spots of water sitting on drivers side inner door stay closer, this I have traced, and need a little more seal down front of door frame..
My main problem now is that I still have the very rear of inner gutters full of water after parking uphill,,, by carefully feeling along inner gutter, its dry until about 600mm from rear, ive even tried sealing the very narrow inner seal behind the main inner gutter.
Any of you fonts of all knowledge know where the fu, sorry, waters getting in please.