I got the following idea for one from one of my cars. I thought about a full on LCD dash cluster.
I sat down with a Chinese manufacturing rep and talked to him about it. Extremely High Contrast, non reflective, custom cut to fit the contours of the OEM cluster housing, 3 video inputs (rearview camera, front facing IR camera plus a spare video input ((I like spare stuff))), 3 USB ports and a trackpad with 2 buttons. Running embedded Linux.
Price for 1000 units? 1500 per unit. The most expensive part is the custom cut LCD and enclosure and software development.
The software development part would be a pain in the arse. Another option would be to run a video out from a DashDaq unit. But that doesn't support (I don't think) video inputs. I also don't think the DD can display (read from the PCM) such things as hard wired lights like the "brake" light, ABS light, etc. The plus here is that they do have the hardware/software already developed. They even have a skin editor, so the artsy types can make their own OEM looking gauges if they want.