 I parked my new Nissan in my daughter's driveway and took a couple of items into her house, I cam back out to get the rest and my car was gone.  I look around and see it sitting in the neighbors yard across the street in their bushes.  I walk across the street open the car and push the button to start it and move it back in the driveway and this time I set the parking brake.  I immediately call the dealership and get told to bring it in for them to look at.  After the dealership having my car for a month which is longer than I had it before this happening they tell me they can't find anything wrong and for me just to always set my parking brake but when it happens again to not move the vehicle just call them immediately and they will come get the car.  They also told me that most likely the car wasn't all the way in PARK thus it rolled across the street and hit the neighbors bushes and because when a Nissan  Altima hits something the transmission automatically puts the car in Neutral that is why I was able to start it without it being in PARK.  Initial questions from the dealership were 1. When I got back in the car did I have to shift gears before starting it.  NO 2 Did I recall hearing anything when I opened the car door.  NO  .   Problem I have with this logic after getting my car back I ran a series of tests.  1. No matter what gear I have the car in other than park it keeps beeping and flashes a message to put car in park.  2. I have reached out to several friends who are mechanics to find out if it's the truth that when in a collision that in the Nissan Altima the transmission really gets put into Neutral(of course I don't want to intentionally hit something to see if it  is true or not).   To be noted also I have numerous friends and family and this is my third Nissan Altima and this is the first safety issue I have had but to me it is a big one.  I will say one of my 2014 Nissan Altima's did have an issue with the entire console constantly going out sometimes for a few minutes sometimes for a day after 18 months and over 12 visits at the shop they replaced it but after a little bit it started doing it all over again which is why I traded it in June for the 2016 because I was tired of constantly having to spend half a day at the car dealership why they tried to repair my car.