If your headunit supports a remote control you can get a device that will make the steering wheel controls work. It costs about $80 USD last I checked though. What you do is connect the device to the controls and have it discreetly point at the HU (usually by running a wire up, near the top of the windshield, pointing down). Then you program the buttons to do anything you want. It supports many buttons, so you can go to Radio Shack, add buttons and get more usability. Of course I forget the name of the product, but there's at least two different ones out there that do the same thing.