I replaced my cabin air filter today and saw a small accumulation of leaves and debris which I promptly cleaned. I couldn't help think about the time I was riding in a Nissan Pickup I had, it was old...and I began to smell smoke, and figured someone was burning leaves, so I drove on. Then the cabin began to fill with smoke and I saw a glow under the dash on the passenger side. I didn't have a fire extinguisher and was not too close to a fuel stop. So, I sped up to get to a station with either a water hose or a fire extinguisher and tried to beat the now flaming plastic dash underside and ended up with a molten glob of plastic on my inner forearm which I slung into the passenger seat, which burned a nice hole in the seat. What had happened, was, as you might by now guess, that the accumulation of debris, choked the fan and the fan got hot enough to ignite the leaves. Just my thoughts...peace....yea, I still have the scar, the Nissan drove for 4 more years.