European Opel/Vauxhall vehicles have OBD-II starting from 2001(petrol).
ScanMaster-ELM v1.4 (with ELM327) works with older (OBD-1) Opel/Vauxhall/Holden vehicles starting from approx. 1996/1997.
http://www.mp3car.com/vbulletin/showthread.php?t=91746
The list with supported vehicles is here:
http://www.wgsoft.de/download/opel_ecu.htm
Wladi
www.wgsoft.de