I was towing the vehicle with my Class A RV. It was a total loss nothing could be inspected. I was in hour number 6 of our long drive to Key West. I looked out of my left side mirror and noticed smoke coming from behind my RV. I immediately pulled off the interstate onto the shoulder. I moved behind my RV and noticed the vehicle was on fire. Within in seconds the fire engulfed the whole vehicle. I had seconds to unhook it from my RV. It took me three tries to unhook because of the smoke. I eventually got it unhooked and went back to the front of the RV and pulled forward out of harms way.