@M3W55 is it only restricted to a mileage limitation (20.000km) or is there an age waver ? (if the car is say more than 3 years old when i bring it back from abroad).
I am sure the Police would not know the difference, but in the UK a sharp-eyed MOT (annual roadworthiness check) tester might spot the non-compliance on a converted EU4. No doubt our continental owners will be able to tell you what the comparable test requirements are in the rest of the EU.