Dead Rat. We had a smell in our vehicle that continued to get worse and worse. I really did not know what to do or who to call. After an AI search I realized it could be a rodent. I called BMR because we have been taking or vehicle there for years and made an appointment with their certified A/C Tech. He went through the system and found a rat had got up inside the system and died on the cabin filter. the rat was removed, a new cabin filter was installed and the system was deodorized. I hope this does not happen to anyone else, but if it does, you know who to call.