Try using the key in the rear door lock and the glass should drop, if i remember right ? the info for recallibrating the back glass is on here
somewhere.
Then when the doors open you might want to operate the switch on the rhs a few times ;)
if i remember rightly they come as a pair, slave and master with the hose,
Could be wrong mind, but it wer some daft arrangement like that, still no great problem to sort tho ;)