Nope, isn't as easy as it has been during the 90s.

Ever had to deal with abominations like CAN-but-not-really-CAN like PSAs own VAN? Having to find out which model has which bus? Non-standard size cutouts / bays? Alone the FW versions i had to test of Alpine / OEM adapter products to get steering wheel controls working. The PDC i couldn't.

And MOST is a different topic.