Currently it's 3.9 degrees here in Indianapolis. Last night it was 1. something. The wind chill is FAR below zero.

Yes my 300SD has been plugged in. It sits on the street so it gets the grunt of the wind chill. It started right up with no problem yesterday and today. Yesterday I plugged it in about 2 hours before departure. Today it was plugged in all night. I just turn it on till the glow light goes out, hold the pedal to the floor and crank. I have started it without being plugged in down to about 12 degrees.

They funny part is... it's SOOO cold out that while driving around last night the temp never came off 40 degrees C. I have since added some cardboard to the radiator and now it get's back up to the normal 80. The heat isn't nearly as hot at 40. I made several stop's last night, each one about 30-45 mins, and when I came out to the car the temp was all the way back to zero. The wind and cold air cooled the engine down very very quickly.

I wish I had 2 keys so I could just leave it running.