What's the point?
80+% of the stereos capable of displaying the output on the market are already Android The remaining are either Windows CE or some other Windows variety.
This feat of engineering is useless. It is now chepaer for Sony to take its existing Walkman app with all software for it and shove it on an Android stereo instead of making a stereo from scratch. Same story with other major manufacturers. While the resource required to run Android is more, the bill of materials ends up lower because of lower licensing (you can just take stock AOSP and pay nothing to Google as the system does not connect to its services). Cost of support and development is also lower as you can use off the shelf apps. Cost of third party integration f.e. to SatNav is also lower - you can take an off the shelf SatNav app and so on.
An example of the end-result can be found on Amazon - just search for Double Din Bluetooth stereo and see how many of them are obvious Android (or Windows CE) devices. Probably > 90%.