Dead Mercedes

[Darwinian]

I've just posted this over at mbclub.co.uk but suddenly realised that that are quite a few petroll/gear heads here as well. So, can anyone solve this little but very annoying problem

I have a 1998 C180 Classic that's been parked up the side of the house for several months.

When I came to unlock the car as I normally do with the key fob, nothing. My first thought was that the battery for the fob had died but on further inspection I noticed that the little light was working so it couldn't be that.

I had to open the car with the actual key and when I tried to start the car, again, nothing. Couldn't even turn on the ignition. Nothing worked, not even the radio, not a flicker of life.

Ok, I thought, the car battery is obviously dead. Not a problem, I'll open up the boot (which is where the battery is!!), get the car charger and charge it up.

This is where my problems started. Obviously I couldn't use the key fob to open the boot, nor could I use the boot release button in the car itself so I attempted to use the key. Wouldn't work. For some reason the key would not fit the boot lock at all, something that I was unaware of as I'd never attempted to open the boot this way before.

So, here I am with a car with a dead battery and no way to charge that battery apart from maybe attacking the boot lock with a power drill.

Just about the only thing I can do is open the bonnet, which of course, unlike most other cars, has no battery in.

Is there anyway that I can give the car some sort of power from the engine bay just so that I can actually get the electrics working and open the boot with either the fob or the boot release?

Basically, I need to temporarily power up the cars electrical system without having any access to the battery. I was thinking of connecting my Lexus's battery to the terminals of the Mercs rear plate lights to 'trickle' some power in. Thoughts?

Or any other suggestions to get access to the cars elusive battery would be greatly appreciated