In reply to:

Is it possible to hardwire the car's remote wire (the one running from the steering wheel remote to the stock headunit) to the tuner module and use the Buttons Codes display function to read DIRECTLY from the steering wheel button pushes?

It depends on your car's steering stalk. For instance, I was able to make an adaptor for my Peugeot 405 using the information on RioCar.Org. (Hmm, I thought there used to be circuit diagrams in there, too).
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Toby Speight
030103016 (80GB Mk2a, blue)
030102806 (0GB Mk2a, blue)