My Vectra has a blanking plug where the Traction Control Switch sits, so after reading a few threads on Vectra-C, if there is a blue plug behind the blanking plate, there is a chance that after fitting a TC Switch, you may be able to turn it on/off.
Rang the local dealer today, and they even had 1 in stock! Went a fetched it, fitted it..........and nothing. It lights up, but doesn't allow me to turn the TC off.
Apprently later models with Full CanBus don't work most of the time. Oh well, looks better than the blanking plate.