How ironic. I am excited because Verizon just shipped my Android Eris, which by the way, I found a site online that has an OEM video-out cable. In addition I also found an Android SDK that exports your Android phone display to your PC and you can control it with a mouse similar to MyMobiler. You can also video record your screen with it. So...to answer your question..why yes!...I would say now that the Android community is evolving more each day and you can use your Android as a CarPC.
The SDK is called Android Screencast. You best believe I will be testing this out when I get my phone. I utilize so many Google apps and services it only made since for me to make the switch from Windows mobile to Android and with the Android screencast, that just put the icing (what yummy icing it is..) on the cake.
This blog talks about it: http://www.sizzledcore.com/2009/12/2...phone-from-pc/
I know this may not exactly answer your question because you still technically need a PC for this app but I still say that with such an open development community, you could probably create your own app or search if your phone has a hack for video-out, which would enable you to connect directly to an external display similar to what was done with iPhone or Samsung Omnia.