This has come from a French national law that then spread EC wide without anyone thinking the obvious that there is no point in carrying spare bulbs if you can't fit them. Yet the EC auto components lobby is so strong that no one has come up with the subversive idea of forcing manufacturers to make light fittings that a driver can change. So you just comply with a daft rule and meanwhile your car gives you nothing like the fuel economy the EC promises you. Think of the EC as a conspiracy of unelected bureaucrats paid by us to help a few rich people make a lot more money and you’ll be getting close to the truth.