[reiderM]

That leaves the steering column (for sure the easiest ones to use are Prius) and the throttle pedal (just because I don't know what would have a nicer throttle pedal, I'm open to suggestions of other electronic pedals that would be more suitable in a sports car).

Depends if you want floor mount or wall mount. Prius pedal is a good option for wall mount.

 

[reiderM]

... I note that there are only 2 conductors. So, seems like on the Gen 3 Prius, there's presumably just battery voltage headed to the compressor and some signal wires. So, perhaps there's an inverter module on the compressor itself? Ugh.

I don't think this is necessarily an issue, often the controls for these compressors are just a simple PWM signal. Otherwise probably CANbus, are the comms wires twisted pair/shielded?