Android Auto/Car Play don't require giving the car access to anything. It should just be a simple video signal output, touch screen coordinates, and audio output/input line.
And I'm pretty sure that is how it works, unless cars are applying screen reader/etc technology (TVs do that, so I wouldn't put it past car manufacturers...).
I'm pretty sure this article is talking about bluetooth, not Android Auto / Car Play. The bluetooth car protocol sends a copy of your full address database to the car because it's a low bandwidth protocol that minimises sending data back and forth while the user is interacting with the hardware. I would never pair my phone to a modern car with bluetooth.