Nick you may well be right and I'm not belittling your knowledge but the credentials of wikipedia means nothing as anyone can write stuff / alter stuff on there.
You obviously work for a remapping company, do you ask permission from VW, Audi, BMW or Ford before remapping their cars?
I doubt it very much. So going by your logic you are committing a crime so why haven't the big manufacturers shut you and other remappers down?
If a customer owns the car I can't see how any manufacturer could intervene.