I didn't leave my stuff in the car all the time, but on those two & three-nighters I sometimes left the amps in over night. I always TRIED to bring in the keys. But when I did leave stuff out, I always covered them it with nice, heavy blankets. It seemed to minimize the frosting and brittleness. Of course, I always got to the next job a little earlier to let things thaw before the job. Always try to let the equipment acclimate to the new temp before turning on the juice, otherwise.... CRACKLE city.