We have a Mercedes S500 that i don't drive often but i did last night. Put it in the garage, walked inside with groceries and closed the garage. I went to move it out this evening and the battery was dead...I left the head lights on.

The battery is in the trunk and I found out you can't open the trunk on an S class with the mechanical key or with out power

Good old internet to the rescue. Seems that there is a metal plate on the passenger side front floor that hides a couple of large gauge positive terminals. Took a spare battery and some jumper cables...positive to the underfloor terminal...negative to the under-hood strut tower and I had enough power to use the remote trunk release which gives me access to the battery. My big commercial charger is in the trunk tonight charging the battery.

Nothing to do with boating but you never know who might need to have this little secret revealed. Sure saved me calling Road Side Assistance on a Sunday night.

I swapped out a battery on an 04 S500 and it really threw the computers off. Ended up having it towed to Brumos in Jax. They reflashed something and it was g2g.

really????? im puzzled,,all the ones i work on the headlights go off when the ignition is turned off but the parking lights stay on..try putting the key in the trunk lick and push on it with it ke in it,,my beemer you have to turn and the trunk will open..

Mike I turned the key every way I could...no go. I called MB today and they confirmed that what I did is what they do with road side assist. The key opens the door but not the trunk. You just need enough juice to operate the electric trunk release.

Every BMW i had when you turned the key in the drivers door every lock including the trunk unlocks...not MB.

My partner has an 89 Porsche 911 that he had to power in thru the cig lighter once to get his trunk open...dead battery.

These cars are great but very vulnerable to simple stuff...example...in my S500 I lost a crank position sensor once about 2 years ago...turned over ...no fire...I called MB Parts...$585!!! + 4 hrs shop...phuk that!!! John went to AutoZone...$49.95 and an hour + three Mick Ultras and HELLO No Problemo!!! you loose one of those on the road at night you are VSF!!!

Just another example of why my wifes new Camaro convertible is much easier to live with than her previous BMW 750. Bimmer was nice but too many little problems and issues that I had to have our dealer fix.

We had 4 BMWs prior to the Benz. BMW= Brought My Wallet..as far as the dealers concerned. Once our MB was out of warranty I found some Certified Mechanics that broke away and started their own shops...at least a 50% savings...especially with computer flash issues.

I wish my wife wanted a Camaro or Corvette...last performance car was a BMW M5...she said it was too hard to steer...I gave up after that. I drove a new Camaro SS not long ago....the dealer had to pry my hands off the wheel...love those cars.