The BMW 5 GT, a new category or just another retro failure?

When I recently walked through the streets I spotted a car that I thought is the new BMW 5 Series Gran Turismo (BMW 5 GT). Well, in reality it was a Citroen C5 (2nd picture) and of course I discovered my error when getting closer to the car. And of course the two cars are not really looking like twins but at least not that different from the back neither. And, for a car that is supposed to define a new category, at least that's what BMW and the motor journalists are claiming, the car should look more unique.
Well, if you take one more step back, you will actually find out, that similar cars did exist in the past. I only pictured two of them, the first and second Audi 100 Avant and the Tatra 613. Do they look familiar to you?
Now, there's one problem. These cars were all not very successful, to not say they were a failure. No wonder, that for example Audi decided to build a proper station wagon as a repacement fo the pictured Avant. So, BMW might well face a problem. At least for me, it's very unclear why I should buy the 5 GT instead of the better looking coming BMW 5 Series Touring. But, let the market proof whether I am right or wrong.