[artplumber]

You could have done what my Dad did to an old Vauxhall on the Stelvio pass:


wrap a pair of pantyhose as tightly as possible around the leak (multiple layers). We sold the car a few years later with that "repair" still holding together.

OTOH that space doesn't look like you might be able to do even that.

I guess I'll have to sell the A6 soon......