I've heard that the 'trigger speed' is actually very close to the posted speed limit- something like +2mph.
Is this true?
Most car speedometers are only accurate to plus/minus 10%!

and re: foreign plates:
A motorcycle riding friend in the UK has his bike registered in Germany and in England. While in the UK he rides with the German plate and swaps it when he goes to Germany. Sort of silly, but that's what kids do.