Because it actually is an A5 and not an A7. At least, that holds for the Benelux. I do understand the confusion, as they are very similar at first glance.

I think it's an A5 Sportback

http://en.wikipedia.org/wiki/Audi_A5#Sportback_.288TA.29

Because it is A5 everywhere. A5 and A7 are different models, not different names for same model. And A5 also has an 5 door model available, although it is not sold in states.

source: http://en.wikipedia.org/wiki/Audi_A7 http://en.wikipedia.org/wiki/Audi_A5

Audi(and heck even BMW, Merc and non lux makers) sell many more variants of their vehicles in Europe. Estates/Avants/Station wagons are the SUV of Europe. Its much easier to make 30+ mpg in one of those than a body on frame V-8 suburban...