Enquired at my local Vauxhall Masterfit (Dalgety Bay, Fife) regarding getting cruise control fitted to my wife's 59 plate Vauxhall Zafira and was amazed this could be done for as little as £67 all in. I was told that the vehicle needed to have a clutch pedal microswitch (likely) and a brake pedal microswitch (definitely) already installed otherwise these would be additional. The cars computer needs programming to tell it to enable the crusie control function.
Also said that on some other models an additional wiring may have to be done at an hours labour cost.
So had it done today and £66.06 later its all fitted and working.
Worth a phone call i think if you want Cruise control. I can post my reciept if anyone wants to see it for part numbers or whatever.