I too would like to know if there is such a way. The other day it got down to 25 degs. and I forgot to plug my '80 300SD in. She did not want to start. I then plugged her in for about 2 hours, and she kicked right over. It is because of this I don't drive the car to work. My wife drives the car to her work, but she only works 5 hours a day. It is just when she has been sitting for about 8 hours that she doesn't like it. My neighbor said his grandfather, in upstate NY, would light a fire under his diesel farm tractor to warm it up. Obviously this isn't anything we want to do, to our Benzes.

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1999 MB SL500 (110,000 mi)
2004 Volvo V70 2.5T (220,000 mi)
2014 Tesla Model S 85 (136,000 mi)
MBCA member