Well it's only partially successful with HGV speed limiters - going downhill the driver just puts the truck in neutral and 90mph is no problem, (can't think of any other way for them to flash past me so quickly when I -ahem- am obeying the speed limit)so just think of the cash we will all save in coasting beyond any such limits.
Personally I think this is just another scare from those who want the uk to leave Europe.
That's it! Just put it in "angel gear"