More than likely, it's just a faulty brake pedal switch. Seen this multiple times now, and a new pedal switch fixes it every time. Lights and brake mechanics still function correctly, it just starts without having your foot on it.

 

Right. But they would still need to touch the brakes to shift out of gear. I don't see the child hazard for an idling car in park.

 

The 2 features of the Porsche I wish they didn't give me is the left hand ignition and the "brake pedal start". The minuses just outweigh the pluses, especially if you have several cars.