If you were sufficiently motivated you could build something like that using off the shelf parts.
For a 911... All you need are 5 Raspberry Pi's and 5 high res screens.
Or a long rectangular screen with one Raspberry Pi but getting a curved one to match a 911 dash may be all but impossible.
GPS, Full internet access and a whole host of audio video options are available today for the Raspberry Pi for not a lot of money. The only big issue is the inputs from the various sensors of the car but with a little research I'm sure you could solve that.
I use one with an additional digital audio card as a media player.
Here's my setup. The silver plug lead at the top is the optical audio out for the surround sound system.
