New vehicle delivry drivers

On the M4 last week
passed at a great speed by 4/5 new MAN Vehicles Chassis /cabs heading west.
If I was the purchaser of these vehicles I would de somewhat IRATE to say the least, at my new vehicles being thrashed down the motorway
before they have even had any chance of being “run-in”
Are Speed limiters activated by manufacturer, of by dealer when prepared/delivered to customer??
any ideas??
thanks