flat battery + locked doors = help!

Feeling rather stupid having managed to completely flatten my battery with all the doors locked ('90 7 series). Even worse i can't seem to get the manual override for the lock on the passenger side door to work - the key turns 90 degrees (with the handle up) but lock wont shift. Any ideas? Do i need to turn the key beyond 90 degrees? Am reluctant to try in case the key breaks. Can't access car through the trunk as rear seats dont fold. Is it possible to open the hood from the outside to get to the battery that way? thanks.

if im not wrong but isen't the battery in the trunk?and im sure you can open it.. pluss you cant open your doors? drivers door? thats vey weird you should be abule to get in the door with the key ....

The battery is under the rear passenger seat, actually. Try doing the key trick on the driver's door, and then manually unlocking the passenger door from the inside, maybe?
Also, even though your seats don't fold, there might be an access through the armrest thing in the back seat. Many of them lead directly to the trunk, if you can find a kid small enough to climb through it and unlock the door for you. (Don't laugh...it's been done)

Also, just a note on the key trick...sometimes you have to actually do it 6 or 7 times in a row to make it work. Almost like priming a pump, kindof.

Tried the key multiple times - definitely doesn't work on the drivers side. But DOES work on the passenger side, though you think you are about to break the lock cylinder or the key it is so difficult to turn. Needs multiple goes, simultaneously lifting handle and turning key. Could be that my lock mechanism is simply old or worn...? Now have a running car again. Thanks for comments.