Is it entering parking mode when the car shuts off?
Which positap did you end up using? Strangely I've just done another install in another Model S (manufactured in the same month) and the positap doesn't seem to be making contact with the switched wire behind the mirror. I think the 20-22 AWG positap I used last time isn't right, and I need one for a smaller gauge wire. Did you have trouble with the 20-22?