I bought this truck several months ago and it had a strong cigarette smoke smell. I had it completely shampooed - headliner and all and it completely cleared the smell. However, now with winter and running the blower at near high, the smell is still very strong from the heater vents. Since there is no cabin air filter, what can I do to deodorize the vents? Is there someplace I can spray an air freshener into the cabin air intake?