I always thought GT, Gran Turismo, means a 2 door, 2+2 seater, front engined, rear drive vehicle. Where does this 3ser GT, fit in with what the motoring world knows as a GT. A 6series or Maserati GT, are GT cars, they offer fast pace over long stretches, but are ultimately not mid engined supercars.
For BMW to stick a GT badge on a MPV or hatchback again, is really an insult to the motoring world, as all it is, is clever badging to create a sense of performance/style from the model-line. They trying to win buyers with a cool name attached to car which normally would be classified as a MPV or hatch. Because MPVs are seen as boring people movers, a GT moniker sounds nice and will add a bit of pizzaz, as GT sounds better than MPV/hatch, but highly irrelevant to the type of car.