I have been on a mission to get Google Assistant integration in my Tesla. This solution is probably the best I have found thus far. Using the Flic 2 and AudioBT Plus, I am able to access Assistant with the click of a button.
Some added benefits include being able to hangup a call without touching the screen. The whole Bluetooth button integrates with Tasker. You could basically create a 3 command FOB replacement with advanced tasks if you set up the button with Tasker commands. Basically a better key FOB for $25. The button also will work for my iOS friends. However I am not exactly how advanced integration would work.