Yes. Currently, I have the basic stock unit (which does not include touchscreen nav). I find it wierd that the steering wheel controls gets affected and disfunction when I install a screen. I have also heard from the agency that in few months they will have screens that does not affect the steering controls. However, it would be almost double the price of the current one.
About the Pioneer you've just installed, is the iPod plugged from the screen itself to the iPod. I mean, will there be any wires hanging around if you wanted to connect the screen to the iPod. Or can you connect it while the iPod is in the glovebox and you control it from the screen? If you have the required antenna installed in your car, can you display TV in your screen?