Isn't it cool to use real gauges with a race game, offcourse it is so I went to the scrapyard and found myself an electric adjustable, heated chair and a dashboard from an old Saab 9-3.
Wired everything together using an old PSU from a computer, and connected to it trough CANBUS.
After reading out some data I have found out that I could use the Rpm dial and send my own values the dial.
After that I found out that the speedometer uses a frequencie to display the speed.
So I have bought an Arduino and fiddled a bit with pwm and tone();.
After one week work I have got it all working and made a prototype from an old table and some pvc tubing, connected the chair to the PSU and used the original button to power the heated pad.

Working:
Speedometer uses pwm
Rpm dial uses CANBUS
fuel Dial uses pwm
Coolant temprature dial uses CANBUS
gear selector uses CANBUS
ABS light using DigitalWrite just on and off
Program is written in c++ and works with Project Cars