I was driving at 45 mph down a country road. It was 90 degree's out today and I had the A/C on high. Out of no where my cab began filling with smoke coming from the passenger side vents and under the dash on the passenger side and a burning plastic smell. I quickly pulled over, shut the truck off, pulled the keys out of the ignition and popped the hood. As I was getting out I noticed the blower was still on blowing cold air and smoke into the cab. I turned the A/C control to off and it continued to run. I looked under the hood and could not see anything burning and could not see any smoke. I opened the glove compartment and the smoke began rolling out. I called the fire department and then a Highway Department truck happened to stop because he seen all the smoke rolling out of the truck. He asked if I was ok and if I needed anything. I asked him if he had any tools and he said yes. I told him I needed to disconnect the battery before the whole truck goes up in flames. He found his wrenches the same time the fire department arrived(which happened to be about a mile up the road) and the fire department disconnected my battery and the smoke stopped. Once the situation was under control I contacted my salesman on his cell phone who gave me the number and name of who I needed to contact in the service department to get it towed in at no cost. I contacted the service department, they sent a wrecker to me and it was towed to the dealer. Please keep in mind I just bought this 07 Silverado Z71 3 weeks ago, used with just under 18,000 miles on it and with the remainder of the factory warranty. When we arrived at the dealer the service department was excellent. They met me outside with the tow truck and got the truck in as soon as is was unloaded off the tow truck. They looked it over, found the problem and had it fixed an 1 hour at no cost to me, all covered under the warranty. The service guy told me that the blower motors used in all full size Chevy, GMC & Cadillac trucks and SUV's are the same and this has been happening alot in these vehicles from 2006-2009 but this is the first they have seen that has actually burnt. Luckily I immediately knew to disconnect the battery because if I would not have there would be damage to the truck but since the battery was disconnected right away I have absolutely no damage at all. The only damage was the blower motor and wiring. They replaced the blower motor,blower resistor and connector. My dealership was Hare Chevrolet in Noblesville Indiana and they were absolutely great to me. They took care of me better than any dealer I have ever been to and I recommend them. I had bad luck that happened but I had good luck to be right down the road from the fire department, had a highway department truck stop with tools in it and that Hare Chevrolet stands behind their vehicles and work and takes care of their customers. Kudo's to Hare Chevrolet in Noblesville Indiana. Great Dealership!