In short, you are basing your question on an assumption that is in fact incorrect. Please allow me to elaborate...
When you buy a music CD, movie DVD or software title in the UK, its packaging will somewhere state that you are in fact only buying a license to use it and must not copy, alter, distribute or reproduce it without written consent. this is also common knowledge, pushed by adverts from folk like FAST all the time.
When you buy a car from the UK, its a different matter indeed. You do not have any such laws prohibiting you from doing any form of modification to it and the general consensus is that you can do as you please as its your hardware. Much the same as your house is when you buy that. This includes the ECU and its control software.
Should Bosch, Siemens, Weber etc or indeed the software owner, (likely the vehicle OE not the manufacturer) choose to challenge this in a court of law, and win, they could then prove copyright infringement and stop us doing what we do, but until such a case happens, (And rumours have circulated for a long time that its about to) the owner of the vehicle can ask us to do whatever we like and we are altering his equipment with his consent, which of course adds the legal question was the owner at fault too? Its a minefield that the manufacturer's have chosen to avoid thus far, enforced by the fact that modification of ecu software does in fact create/save the OE money in general as long gone are the days of blow ups, people now buy vehicles because of their remapping ability (Much the same reason as Intel released their clock lock policy and then overtook AMD within months...) and of course faults with the vehicle can be rejected due to a remap if they so wish as not modifying is usually part of the warranty agreement. A win win for them. Hope this helps.
I must say, you have flipped from the data protection act last week, to copyright infringement this week. A more paranoid administrator might think it was a personal vendetta by someone trying to show that he doesn't know his job... Lucky I do, so i don't think that! 