Battery dead can't get in car.Not even with key.

Sometimes you can hook battery charger up to starter battery terminal and charge it that way.
Sometimes you can remove rear seat to access the trunk, there might be an emergency release handle to pop the trunk.
I'd have to look at it, I can't be positive.

If the battery is under the back seat like some models, charge battery.

Buy a cheap battery charger that plugs into the lighter socket. The battery will come up enough to pop the trunk. If you are in a hurry, you could power up the system under the hood by attaching 12v to ground and the back of the alternator if you know how.

Hi Your S class has two batteries. The smaller one is located in the engine bay, and the bigger one in the boot (trunk). No need to access any of them, simply open the door with key, insert key to start engine, you will notice that not all ignition lights will come on, but the engine WILL start, and the batteries will be recharged after a short while.

Power the car's electrical systems with another car using jumper cables attached at the connection point and a good ground under the hood. That should make the trunk release work.

This is a common problem. Your alarm was on when the battery went dead. When the alarm activated, the hood/bonnet opening lever locks to prevent thieves from opening the hood in case the top is down. Some boxsters have a jumper post the pulls out near the fuse box. However, I do not think the 1997-1999s have this post.

Buy a male-to-male cigarette lighter adapter at the auto store. Connect between your car's cigarette lighter socket and the other car's cigarette lighter socket. Do not try to start the ignition or the any other electronics. You should not even need the key in the ignition. You should be able to pop the door locks with the remote and open the bonnet.

You may also need to recover your radio code: http://www.a2dvoices.com/realitycheck/porsche/

open trunk, disconnect rear trunk light. use jump box and connect wires to pos neg on jump box. this will give u enough juice to open doors, I have done it twice. easy to do

Pop open the hood (bonnet) on the left isde of the firewall there is a red/black battery connection so you can jump start the car without getting to the battery.

Posotive can be found in hood driver side next to fuse box. It is a small rectangle box. You can hook negative to any solid ground on the car.

I have the same issue (battery is completely dead in my 1998 Mercedes C280 and I can't pop open the trunk). I looked under the hood and have no idea where the positive charging post would be - can anyone help me find it? Thanks