Has anyone upgraded their stock heat exchanger/blower motor or maybe installed an aftermarket auxiliary heating system in their M1009's? It's gets cold in New England and I sometimes make trips up into Maine and NH when it is Zero or below out. Truck runs great, but as for heat, not so much. I do block off the front grill of the truck . I also have some inexpensive seat heater pads in the front seats, which help. They work great, but they do nothing for my feet.