I had been driving about 15 minutes, when it just shut down. I tried restarting, but it wouldn't start, and looked like smoke was coming out. I had it towed to a dealer near my home. After 2 days, they can't find anything wrong with it. No codes come up on their diagnostic computer. They started it right up, and tried to run it until it died, but it didn't die. This first happened a few weeks ago, and the same place replaced the spark plugs and wires and it seemed fine until this happened again. I'm picking it up from the dealer tonight, and now I worry that it will stop in traffic again. Doesn't anyone know how to diagnose car trouble anymore?