I've added 3 audi gauges using a WRX pod.  Pics here.

http://my.tbaytel.net/guskers/

There is no substitute for good old VDO oil pressure and temperature gauges.
 If I hadn't installed these my engine would likely be blown up, as I had a
serious crank/oil contact issue that was frothing oil and resulting in very
erratic oil pressure readings.  The stock oil pressure warnings did not give
any indication of this.