found this whilst the site was down *coughukmkivscough*
if you go to your car hold the ac/econ button and the button with the guy and the arrow facing up on it then your 2 screens which normally display degrees C turn into small "computers" and you are able to get LOTS of info about how your car is running. it even has another spedo in it.
anyway im not too good with words so heres the link. OH and im waiting to find out what all the codes are from my VW stealer.
http://uk-mkivs.net/forums/t/201425.aspx