That is an excellent point! A good defense counsel would have him plead the 5th at trial, and then ask the prosecuting officers if they have any evidence of how he got in the car and who started it and input the address. If they don't, then in closing argument, the defense could argue that a friend or anyone could have put him in the car and told it to drive him home. If I'm on that jury, I would let him off. Most likely, it would be enough of an argument to get the prosecutors to reduce the charge and allow him to plea out without killing his insurance or bank account. They don't want any precedents to be set.