Audi efficiency premium

Good day, perhaps one or the other has already seen that when buying an A3 or A4 there is the efficiency premium of 2000 euros. http://www.wirthgen.de/holm/aktion_effektive.php However, this premium is linked to certain conditions. I simply decide that I currently have a Golf IV. This is a car of the VW Group and thus the car is excluded. Can anyone explain to me why this is so? I am opposed to such conditions. n why can someone who has a Ford or Opel benefit from it and I, where I have invested in this company at an earlier time, probably look into the tube? That can’t be it! I can only imagine that they want a VW or Skoda driver to buy again from VW or Skoda. But that will certainly not be the case with me. That’s why I can’t understand it! I’m curious about your opinions and reasons. the back door still a chance to collect the efficiency premium? My golf is currently worth about 800 euros…. MfG