[ifone3gn00b]

So here's my situation.
I have an iPhone, and a screen in my car that has multiple video inputs as well as an iPod dock cable. I can play videos, and listen to music on the screen's interface, but for calls, I would like to be able to view the calls and answer them on the screen, instead of on the iPhone. When plugged in via the dock connector, my iPhone mutes music that is playing, and plays the ringtone over my car's speakers, but I have to answer it on the iPhone. It's easy enough to just use my bluetooth headset and answer the calls that way, but is there a way to get the caller ID to show up on the screen? Is there some app that will allow me to output the direct screen image of my iPhone to an external touch screen? Or am I on crack?
Thanks

edit: There is another reason for me asking this. When the developers release their GPS navigation apps, I would like to be able to view it on the screen as opposed to the iPhone.