What's this button?
 

The two buttons on the left on the rear passenger doors... What are they for?
http://img511.imageshack.us/img511/4482/29jw2.jpg

They determine whether the seat control affects the rear seat or front passenger seat. Press the leftmost one (the one that points to the front seat), and you'll see that you can adjust the front seat position with the rear controller. Normal operation is when the right arrow button is pressed in.

This is useful when you want to move the passenger seat up to allow you to put a large package on the rear floor. It's much more convenient than messing with the front controller.

Because it's also a way for kids to annoy their mother, it is locked out when the rear-window lockout is selected. That's the little switch on the driver's door. That may be why it doesn't seem to do anything.

This remote seat controller is standard on V-12s but comes with the rear seat package on V8s.

PS. It's only on the passenger side. Safety dictates that nobody can mess with the driver's seat.

Oh that's so cool! I thought only the Maybachs came with this feature.
Is this standard on all S600/S65 models?

I'm pretty sure. I've never seen a V-12 without it. I use it all the time because I carry stuff in the rear. The only time a rear passenger used it was when two IBM Vice Presidents were playing dueling seats on the way to lunch. I had to cut them off with my child lock out.

my early 05 doesn't have them, which is weird since I have the rear seat recliner heater/ventilation.

It's only standard on S600's. It was optional on the 500's....

My father's '00 S500 had it. I got the impression it came as standard on LWB versions in the UK, as most W220s in the UK were SWB. Only the S600 came as standard with the LWB, otherwise it was an extra £4-5k.

My 05 s350 has it.. But i just got to know that you can disable this using the window lock feature.. Sometimes my frinds riding can get pretty annoying fiddling with all the buttons on my baby... Aagghhhh ! Now i have a way to shut em off !