I have the gauge package installed by the dealer on my '05 MCS. Consists of a voltmeter and water temp gauge. The cost was exorbitant, I'd suggest that if you have decent mechanical skills to install it yourself.
The gauges are located at the bottom of the dash console, under the swiches. As such, it's not easy to see. Also, the temp gauge readout is in centigrade, not exactly what I was expecting on a U.S. spec car.
I'd like to add a boost/vacuum gauge, one of the most useful gauges IMHO and great for engine diagnostics. Oil pressure would also be nice. But then, I love gauges and can't ever seem to have enough.
The factory gauges are VDO and can be purchased at many retail outlets. There's also an aftermarket gauge setup that goes adjacent to the tacho, not sure where to buy it.
do it yourself. its not worth the cost from the dealers. all in I paid for guage holder, 2 guages water temp and voltmeter and water temp sender all for less than £50. look in my gallery, i am pleased with the match of the accessory guages.