This whole experience morphed into a discussion of UI design in a way I wasn't expecting.
I still never figured out a good way to make the sketchpad go away. I didn't see any [X] button to close it.
Maybe I am not aware of a necessary finger gesture to make it go away? Maybe I am supposed to "flick" it with multiple fingers or something?
It seems as people got used to gesture based UIs, some have gone perhaps too far and started to add specific multi-finger gestures... Like I see 3 and 4 finger ones here:
https://support.microsoft.com/en-us/help/4027871/windows-10-touchpad-gestures
How To Use Touchscreen Gestures
I bet there are still some people who could get in a model 3 and wouldn't think to use the pinch in and pinch out gestures to change the map zoom.
The Model 3 UI team probably looked at various types of UI options and decided which ones were well known enough to be "fair game" to use in the car UI.
I was a Windows users for years before I got started on MacOS, and the biggest surprise to me was some needed touchpad gestures on MacOS I had never learned on Windows...
Even though I was a Windows user, when it came time to get a SmartPhone, I went with Apple iOS devices because I just found them easier to use.
The lack of consistency between Android apps was more frustrating. I still use Windows laptops mainly, but Apple phone products.