David, You fill in a form at your local Saab or Vauxhall dealer (it's a GM scheme, so any GM garage will do.) I found that my local Vauxhall place was quite sticky about it (I don't look like a garage owner) and didn't process the form, so I contacted the person who runs the scheme centrally and applied (again) via him. Since being a member it's very easy to get the discount - you just quote the number when you collect parts from the parts counter. (Although beware - not all Vauxhall and Saab garages are in the scheme - some are outside.) It's very useful for generic parts (wiper blades, oil, coolant, spark plugs, batteries etc) as the discounts are immense. If you have a vauxhall then some parts are good value, some are a bit less great. For instance I replaced the wing mirror on a friends' Zafira a few months ago, and it was cheaper to buy the replacement mirror from an on-line source than from GM, even with the trade club scheme. Oli. ETA: The website is here: http://www.tradeclub.co.uk/ ... and I'd have thought you could become a member without a VAT number - I'm not sure all small garages are VAT registered and hence doubt they would exclude you for this. Make sure you give them a motor-esque business name tho'; "XYZ repairs" or "ABC engineering" for instance.