I haven't heard issues with auto transmissions, what do you know about autos and long idles? Something to help would be to insulate your vehicle. I thought my 2000 S-10 would be real cold in the winter because my old rusted out 88 always was so i insulated it before the first winter. The hardware stores have this stuff in a roll that looks like bubble wrap with aluminum foil on both sides. They had a sample of it folded up like a little bag that you could stick your hand in. In a few seconds your hand starts to sweat from the heat being reflected. I bought the biggest roll they had for $40, pulled all the interior plastic and the headliner out of my truck and used aluminum duct tape to stick this foil wrap in. I can drive to work in zero degree weather with the heater fan on the lowest setting and the mixture in the middle between cold and hot. I've been planning on running a second battery in my truck, been wondering if a small 12v electric heater would work for a couple hours, then run the engine for 1/2 hour to charge, run for a couple ours again if needed.