Gen I W126? Unlock a door and the trunk and fuel lid also unlock, right?

That is correct unless the trunk is locked with the key. Earlier post says it is key locked. Wouldn't a locksmith be easier and cheaper?

I never used that feature but I see it now in the manual. Learn sumptin' new every day

OP needs to get a new key. Not so hard. I have done it. And then he has a key with all the assigned benefits.

Thanks Guys for your help Great ideas BTW . The owner is going to get a new key made, he said he didn't know you could do that so it will make it easier to look over the essentials .
The car comes from Florida and looks pretty good but....has been sitting about a year so I really need to look it over real good.

Thanks Again
greazer2b

The W126 has an emergency release cable under the rear seat, on the LH side. To get it to work, pulling the release and pressing the pushbutton on the trunk latch have to be done simultaneously.

I've had all seats out of my 83 SD and the trunk completely stripped and never saw an emergency trunk release. Nor do I recall reading about it in the owners manual. So when you say W126, do you mean yours or all?