It would never emulate the front panel buttons, it would only emulate a subset of the Sony stalk buttons (slightly different).

However, all that you would need is to know the resistor values of the Sony stalk and then assign each of the racerboy buttons to a given resistor value. Then it could wire directly into the tuner module.

I'm interested in these values, because I'm considering making my own "stealth" buttons to wire into the tuner module. They would be very small and be integrated with my car's existing steering-wheel controls. All I need is to find some very-low-clearance buttons. Anyone have any ideas on where I can find some?

Should the resistor values be published at the developer site somewhere?