Wanted to share with fellow Teslanauts. I noticed a few times when I was backing the car up very slowly to reposition it, as soon as I pressed the accelerator a little harder it would switch to Park. Turns out it's because I was not buckled in -safety feature. As soon as I buckled up - the car behaved normally. I haven't seen this documented anywhere- so before you schedule a service aptmt, please keep this in mind! Hope this helps!