Car obd and multimedia

So i would like to make a project where i replace my broken in car computer screen with arduino touch screen so i could see obd info from there and also one thing would be cool if i could interact with my 1din stereo aux input. What parts would i need for this project? Which boards

If you just want to display OBD information on a screen, there are commercial adaptors that plug into the OBD connecter and allow you to view the data on an Android phone or tablet via a bluetooth connection.

If you want to do something more than that then you have many hours of study ahead. Start with this thread https://forum.arduino.cc/index.php?topic=659310.0 which covers the CAN bus side of things.

Whether an Arduino is able to communicate with your audio system depends on the availability of technical documentation, what test gear you have and how much time you are prepared to spend figuring out a solution. A car hacking forum is probably the best place to start.

Found this recently, cant remember whether reccomended from this forum or elsewhere, but it would certainly be worth a look RealDash

google arduino OBD
there are many people that have done something with Arduinos and OBD