Cars starting by themselves can sometimes be caused by the devices that start your car with a push of the button on you keychain. Some of these devices can be programmed to start the car at regular intervals, and run for a set period of time. then shut off until the next run time. This is used more in colder weather. I installed one for a friend and wired it wrong. I read the manual many times and it had instructions to program it to start every two hours and run for fifteen minutes. When I figured out the problem my friend son had traded the vehicle. Thank you.
Is there a question here somewhere?