Franglais:
The Italian Polizia Stradale were always keen to raise funds.
As M. 14 says trucks only need to show signs according to country of origin, however spending time at a roadside arguing etc etc.
I know of more than one UK company putting those It. speed stickers on their trailers. I’m only guessing that could be the motivation here, no evidence, but a possibility?Sent from my GT-S7275R using Tapatalk
Yes, I think that would be a more reasonable theory.
Im pretty sure the companies limit their lorries on purpose (Hence the waberers stickers being under the Hungarian limits) despite the drivers break them all the time 
That essentially solves my question, except on some trucks there are only 2 speed stickers, like these ones.
Also thanks everyone for helping me solve this mystery! 