alt Hacker NewsI feel like you could solve that with some constraints defined early in the process—the controls must fit in dimensions XxYxZ, and have K-input wires, and draw at most 5V of power, or whatever. Then the control designer can go off and design whatever they want within those constraints, and the car designer can go off and design the interior of the car knowing what the head unit will require.
That's what the term "parts bin parts" refers to in the industry. If you get familiar with any car brand you can normally tell what brand of car a particular switch came from because they all use the same parts. Corvettes will share a LOT of parts with Suburbans, eg.
You still have the issue of having to build the panels that the switches get installed into, so if you can replace a bunch of switches with a touchscreen interface, you can get on with designing the interior before you even know how may switches need to be installed.