Today I turned on the car, the screen lit up, then went blank. I was in a hurry, so instead of figuring out why the screen wasn't working for more than 10 seconds, I put the car into drive and left the garage. My house and driveway are sloped downhill, so I rolled about 2 houses down before I realized the gas pedal wasn't working and the steering felt heavy.
After Sync rebooted, the car worked after I restarted it. The green drive icon was on, so I'm sure the car was on. On 2 other occasions the car has had no go upon starting, without any issues with Sync. It was instantly fixed when I restarted the car.