Ouch, using a rear wheel drive sports car for a winter car can't be too fun? I live in Minnesota and when we get any snow, my car is all over the place when I do decide to drive it.

 

Ya ain't havin' fun till you're sideways! (Dirt tracker saying)

And having that big power sucking grid called a 'rear window defogger (or what ever)' on a timer helps free up some current for headlights, fan and other useful entertainment. Some people might hook the power lead to the wrong side of the ignition switch and come out in the morning to a warm rear glass but not enough umph to turn the motor over.

I had a Chevette once that was so gutless, GM put an idle relay in that would cut out the rear defroster, heater fan and alternator if the idle speed got too low. Was supposed to keep the car from stalling .... until the battery died from the headlight drain.