I have hot air with the engine off, until the engine cools off, it doesn't have a secondary electric heater, just dumps engine heat. Although mine is a facelift model, key has to be in position 2 for it to work though.
Yeah i suppose that is an option, I've found if I leave the engine running for 10 to 15 minutes anyway before I get in it, once you start driving it takes no time to warm up at all. Literally a minute or two.
I haven't got my owner's manual handy right here; but there is a button on the dash that one pushes for just this purpose. Let's say that it's a cold winter day. The wife, significant other, GF, or just a hooker, needs to run into the store to get something while you wait in the car. You don't feel like running the car and wasting all of our precious resources, so the SLK has this nifty button on the dash that one pushes to provide left over heat in the engine..............Not one politician REQUIRED Mercedes to do this, just your friendly engineers at Mercedes.........God bless......Dennis
This is a really nice feature if you want heat while sitting in the car and don't want to leave the engine running to (providing the engine is at operating temperature when shut off). For a period of time, the coolant will flow through the heat exchanger and the cabin fan will run at a preset low speed. Really nice feature!
My friend bought an Audi 2.5 diesel in Germany that has an excellent supplemental system. It actually has a diesel heater integrated into the coolant system. He uses a key fob to remotely turn on the heater. No ice on the windows, the interior is nice and toasty and the engine is at a nice warm temp before start! This would really be a nice mod for anyone living in extreme winter conditions in the US. First time I've seen one on a passenger car.