My dynotune Heaters say they are 300 watts... and if anybody knows their electricity, 300 watts at 12 volts is 25 amps... and if your engine is running it should be at 13.5-14 volts which drops the amps down 21.5amps... So at a minimum run 10awg wire and a good 40 amp relay and a 30amp fuse.
Should be ok then.

 

HAHA, well you can touch it, but maybe only for a second.
Im not touching my bottle heater..

 

yea no ****, they get pretty damn hot, when jaegmc99's was first installed it was basically melting his carpet.

 

I always either had the seat out or flipped up when I had my heater on so it wasnt an issue, either way, with my HSW heater, it never got hot enough to hurt anything anyway.... I normally threw a jacket over the bottle just so it wasnt so blatantly obvious.

 

My back seat is either folded up or completely removed when i turn my heater on. But mine gets HOT, i know i could put my hand on it, but not for very long.