Sure but decorations are usually surprisingly allowed as aftermarket modifications. Like you don't need to recertify your car for bodykits etc either and sometimes you need to do those to reinspect your new wheel size.

Reindeer steels etc are usually also allowed even if they totally wreck the pedestrian collision rating. Finlands super annoying about all mods even just wheelsizes but you can bolt just about stupid spoilers you want on a car.