Have you tried locking and unlocking the car with the key? Have you tried it from the passenger door?
I wish I could be more specific, but the security systems work different on the different models through those early years and I don't exactly remember. It is my impression that the key should turn off the security immobilizer, if not at the drivers door then at the pass lock or trunk.
The emergency road side service will arrange for a tow to a shop where real technicians work. Real technicians very seldom work on the road... easier to move the car than the shop!
Bosch Master, ASE Master, L1
33 years MB technician