Be careful when using 120 VAC light bulbs in a closed compartment that is subject to vibration and shock ... and/or that could have combustibles (i.e.; mouse nests, etc.) in close proximity.
I just recently received the cold weather kit and I will soon install it and let the group know what I think about it at that time.
I anticipate that it will use about 20 watts as the heater resistance is 7.5 ohms. There is a thermally activated switch that will turn the unit off when the ambient temperature is high enough. Only other componet is a 3 Amp fuse. Pretty simple.
Steve