This is sorta off-topic, except that the motivation is to be able to use a 240V space heater in my garage so that I can rinseless-wash my Model S in the winter without too much discomfort. All I know about electricity is that electrons are yellow, and I figure that those of you who know more would check this forum. The garage's inside access is to the laundry room, which has a 10-30R for a dryer. I could run an extension cord from that. And there's a 14-50R in the garage which I had installed for charging the Model S. To provide sufficient heat I've been assuming I need a 240V space heater; the portable ones I see on Amazon have 6-30 plugs. Would there be any economical solution to powering one of them in my garage?