I want to make a heated steering wheel for my car using hand warmers from a snowmobile. The power source is 12 VDC and the resistance is 10.0 ohms using 25 watts on the low setting and 19.6 ohms using 35 watts on high. That is for one handwarmer, I figure I will need about 20 of them. Will they still heat up since there are so many of them? Will the increased resistance affect the wiring(getting to hot) to and from the steering wheel?