Oh no it doesnt! It's a 3 Series Coupe rival. There is no longer an A4 cab - the A5 is the cab instead now. All Audi have done is introduced an A4 hatchback and an A4 Coupe, badge them as A5, and badge the new A4 Cab as an A5 as well.
The 6 Series is a big wafty GT thats even more expensive than a 5 Series, the A5 is nothing like.
Can people not check the basics before spouting off 'facts'? A simple comparison engine wise will tell you how wrong you are - do you really think a car which starts with a 1.8T petrol or a 2.0 diesel competes with the 6 Series, where the smallest engine is a 3 litre and most of them are V8's?