Hi, to get dashboard info on the computer you'll need to use OBDII. I don't know much about it, but I don't know of any free OBD software. And it will probably be even harder to find suitable software for Linux.
Some one will probably mention that you should have ordinary gauges as a backup if the computer stops working, maybe behind the virtual dashboard screen. They might even be legally required. Again, I know next to nothing about this, so you should wait until someone more expert comes along.