The Co-Op a huge grocery retail chain in the UK use XP based tills. I only noticed them because the customer facing part of them often displays Win errors
Also I know of a large Radiography company whose X-Ray machines all had Dell workstations running XP inside..now that's scary.
The speed cameras are mobile units, the cameras that are in fixed positions are well documented (or vandalised) and so to catch people temporary speed traps are set up. This will allow them to be configured with an accuracy acceptable to the courts. Should there be any doubt as to the accuracy of the equipment used, any good or even crap barrister would be able to get the charge quashed by the judge in lieu of any other evidence (skid marks, etc).
Britain is a strange country for cars, the cramped roads cause a lot of hate AND cameraderie amongst drivers. When the law changes whole groups of motorists will get together to try to test and break it when the day before they were leaning on horns and swearing at each other. Any loophole will be jumped on en masse and so accuracy is paramount with regards to technology used for speed traps. This is all mainly Jeremy Clarkson's fault.
In the UK you possibly wouldn't even need to take them court yourself. Merely report the retailer to Trading Standards (the govt dept for these kind of things for you non-Brits) detailing the advertising for the product at the time of purchase and how you believe the law has been broken and they will do it for you if your claim is valid.
Not only that, if they are successful they can also order other companies to offer refunds/discounts/compensation should they also have sold the product without those consumers having to go through the same process.
Going down this route means the govt not the consumer funds the legal action should the claim be valid and the company concerned dispute their breach of the law. Additionally in the UK we also have the pleasing effect of BBC1's consumer program Watchdog, if they take up your case the company will find themselves having a 10 minute grilling of their services and how they have broken the law viewed by several million prime time viewers. Watchdog is such an institution here that a bad press from them can have very serious repercussions on your sales, and will probably make the daily newspapers the next day in some form (probably the Daily Mail with a headline like "Amazon product lies killed Diana!"). This is what Amazon really fears.