Imagine driving into a pot hole or up on a curb stone, that impact would rattle the transmission quite a bit. Your heavy motor and only the turnbuckle to hold it. It's more a question of when it will break, not if. Sure will be a shame when it does.
Yeah, you're right about the air heating to the battery's. One step further would be to rout warm water around the packs directly. Much easier to do and no loss since the water are recycled to the heater again. Only a extra cycle pump, with an switch inside. That's the way to go I think.
