My Saab 9-3 was in a rear end accident with extensive body damage. After the accident the exhaust was smoking heavily. I had a new Turbo put in, an O2 sensor replaced. Insurance said it was not accident related. 366 miles after repair service engine light went on. Dealership could not find a problem although code indicated evaporation leak. Two days later the car stopped when I was driving...just stopped. Any thoughts on whether evaporation leak could cause this and whether a rear end colision could cause evaporation leak?