This morning it was a bit cool at 20F out. I've been contemplating how I've wanted to install this heater I have. Its a bathroom electric heater. I tested it out the other day and it pulls 1350W. It also has a snap switch on the far side that will kick it out if it gets too hot. I figured it should heat the tiny Insight cabin up right quick! Well, today was the day. I literally just stood it so the exhaust was pointing up in the passenger side foot well, plugged it in and ran back inside. I left about 7 minutes later, but the chill had definitely been taken out of the Insight cabin. Not warm mind you, but it was not cold. 10-15 minutes would do a great job I'm sure.
The next step is finding or making some sort of better mount for it. I think I'd like to place it on the rear deck and have it blowing towards the windshield to help defrost it. That gets it out of the way if I have a passenger too.