Digital Dash

With all the technology available to cars, why haven't they picked up on LCD displays yet for dashboards, or arguably even better, TFT. (see the OLPC project for what could be perfect, as it can be both backlit and ambient lit)

True digital displays open up a world of possibilities, including additional on-dash display of the speed limit, and should speedlimit indicators be machine readable (from embedded wireless in the roads, to OCD signs), that limit can be displayed on the dash alongside current speed.

Brainstorming

• I have heard it argued that the speedo should recalibrate so that the limit is always top center - but I think this is poor as it breaks the existing spacial memory of the speedo dial. (wikipedia:Toyota Sportivo Coupe)
• in case of catastrophic failure (say, crash), e-paper would show last state - give an idea of speed/conditions moments before the crash. (a section of the display could be devoted to a last-5-minute log, but that might be better suited to a blackbox anyway.
• Digital displays allow the "themes" for different purposes or priorities. for eg:
  • In regular mode, you have your basic sedan dash
  • In sports mode the tacho is larger, and speed becomes digital
  • When car is in reverse, display estimated distance on each proximity sensor. Or if the car has corner-mounted cameras, show those in the dash display.
  • A parking mode which engages proximity sensors and cameras also. Could this be automatically engaged after reverse, and disengaged after, say, 15km/h?
  • In any driving mode, some gauges are actually warning signals - and if the measurement is in a 'safe' range, I don't need an alert, but as they increasingly move towards warning and critical levels, I want the alerts to be increasingly obvious.
    • fuel, engine temperature, oil pressure