The Danish car taxation that trebles car prices has some bizarre consequences.
The problem is that lots of people would like to buy their cars in Sweden or Germany to save the tax. However, this would completely undermine the Danish system, so the Danish tax authorities will clamp down heavily on this, showering you in fines and potentially imprisonment, too.
To me, this just demonstrates that the system is broken. If Danish car taxes were adjusted to normal levels, nobody would want to circumvent the rules, and nobody would have to go to jail.