I'm new here. Sorry if I'm posting in the wrong area!
I stored the car for 6 months with the battery disconnected. The car may have been locked when put away, I wasn't there. The other day I opened the door and then attempted to open the trunk with the little metal key. The key would only go in the lock about half way. After much fiddling I opened the hood and could not find a way to jump the electrical system. I called the MB help line and was given ZERO info. So I opened the matchbox sized box just inside the left side of the hood (on top of the fender, I think.) I attached the positive wire of my jumper there and the negative to a nut and bolt about a foot down from there. Some lights went on I hit the trunk switch in the car. EUREKA! The trunk opened. All went smoothly after that.

Why wouldn't the key go in the lock? It does now.
Did my method put any of the electronics at risk?
I just remembered my jumper came with wires that
will feed current through the cigarette lighter recep-
ticle. Would that have worked?

Thanks!