I'm not sure if this possibility has been said before for you guys with the metra kits and can't use your steering wheel controls anymore.
My idea is that if your head unit comes with a remote control, there should be a way to hardwire the buttons on your steering wheel to the board of the remote. Tuck the remote board into the steering wheel then, if it's IR, point it at the head unit.
If the buttons just require that a circuit connection be completed, it'd be easy to remove the remote keypad, solder some wires to the positive/negative part of the button and then it should work. Of course, I've never even looked to see if it would, but I thought it might.
Or you can just order the PAC SWI- Steering Wheel Control Unit that will work with your headunit and not have to do anything custom, like most people do.