2006 Mercedes-Benz R500 - Seat Heaters

safety issue they do that so the seats don't get too hot and make the seats catch fire also it helps save on battery life

none of my other cars do/did that. BMW, Audi, Mini, VW...
Only Mercedes is concerned with this? And how does this help battery life?

it saves juice by turning off, since it uses an electric resistance to heat the seat. Did you check the manual to see if there's a setting for constant seat heat? (perhaps holding some some seconds the button or some other gimmick way )BTW, could you upload night full dashboard pictures? I am a fan of illuminated buttons.

But they only work with the motor running, which then charges the battery...
ya know, I'm gonna go check to see if I can turn on the heated seats without the motor on in my Bimmer! Now that I'm leaving work...ok, just checked.  The seat heaters only work when the motor is running, so no chance of running down the battery.

I'm with desmolicious. If they only work with the motor running it's a moot point.

Not a moot point at all. Todays cars use a huge amount of current.
 
Anything with a heating element is a major drain. Even if the car is running, if you exceed the output of the altenator (and I bet you do at idle) you will drain down the battery. You can do this for a while because todays batteries hold a lot more power then those of the past but eventally they need to catch up.
 
Combine short trips with heated seat, rear window defoggers, electric engine fans climate control fans, maybe throw in an air compressor for a self leveling suspension and hundreds of other power accesories, motors and sensors and you will run down a battery.
 
I won't even get into the effect it has on battery life and and what it does to fuel economy due to excessive load from the altenator.

Not to mention a higher wattage stereo on top of that

And yet Mercedes is the only mfg that has them turn off after a short period of time? And believe me, it's short.

Hopefully you noted that the Hyundai Azera's 5 position heated seats stay on and will stay on the same setting when you restart the car, until you change it or turn them off.

This is a hot topic on Mustang forums. Ford added seat heaters as part of an option package for 2007 but they are the one-temp, auto-off variety. I understand auto-off for a rear defroster but I like the option getting my butt and/or back nice and toasty. GM is way ahead in this area with their choices of heat level and back or back and seat. Not sure if they stay on or not, though.

In both my first car, which was a 96' Lincoln Continental, and my mom's Acura TL which we recently purchased for her, the heated seats actually have MANUAL switches or dials, which could be permanently left in the switched ON position, so that when you got back in the car, theyd be on as soon as you turned the key.
 
In the Continental, they had 5 positions, and were some of the hottest I've ever felt.
 
My BMW 330i's heated seats did not stay on like that after you shut off the car, but they also didnt turn OFF mid way through your ride and were probably the best I ever had. I cant imagine that feature possibly being there for battery use, the current draw is actually negligible, and even if it weren't, the vehicle is designed with these current pulls in mind. Who knows.