318 Trunk Locked Up...need HELP
My 1995 318i trunk is locked up. Everything was working fine, I went shopping for some groceries, locked my car and went to the grocer. I decided to put the bags in the trunk. I inserted the key into the lock, turned the key to the left, pushed the latch button in, and....nothing. The trunk will not unlatch. The key slot remains in the horizontal position, and it cannot be returned to the vertical position. I pulled the key out, and unlocked the car. The trunk remains latched, and again I inserted the key into the horizontal slot, and I am unable to turn the key slot to the vertical position. I am pretty sure the key I am using is a master key.
Any ideas how to unlatch the trunk, before I take it to the dealer?