You said itSome other nut job heating ideas:
1)Unless you are really driving near the limits of the controller most of the time you won't get anything worthwhile.
2)Same thing. My 30 amp PFC charger doesn't put out much heat at all.
3)That would work.
4)Or get some heated seat covers. I've got a heated massage pad that will run on 12 volts, I can drive and get a shiatsu
5)Not worth it unless you are going down a loooong hill, and still probably not worth it.