Via bairy on the MailWatch forums, I've belatedly found the beatroot, and a couple of very interesting postings about how the Daily Mail goes about acquiring some of its anti-Polish material.
Read all the posts, but the jist of them are that a Mail journalist contacted various people in Poland to offer them payment to drive their Polish-registered cars to London to break the speed limit, park illegally and evade the congestion charge to prove that it can be done without the drivers ever being punished as their cars aren't registered here. Why the paper decided to do this with a Pole specifically, rather than any other nationality, is up to you to decide. Anyway, here are the posts:
From the beatroot, 'Daily Mail pays Poles to break the law' and 'Daily Mail knows...'
From EU Referendum, 'Faking it!'
From the Economist, 'Britain's shameless press'
It seems from the hack's email to the Economist that the paper didn't in the end go through with making the drivers speed as that would be against the law. She still offered money in the first place, and if we can take one of the comments on the Economist article at face value, decided not to use one of the people she'd initially contacted as they refused to do the speeding bit.
Great eh? If you don't have a problem with this, imagine the paper doing the same thing with other groups and other negative things associated with them. Not nice.