Where can I get the specifications to make car radio designs so that it would be compatible with Android Auto?

[rofrsa2003]

Car Radio Development

Hello,

I am not a mobile or Android developer, but I am working on the other side, at the car radio OEM development.

Where can I get specifications to make the car radio design so it would be compatible to work with Android Auto enabled devices?

What are the requirements for the car radio side?

Thanks in advance,
Rodrigo.