I'm a huge Audi fan and even I struggle to see the point of the V12 Q7. Yes it has big power and torque figures but it has a huge weight penalty and negates the main benefit of diesel as the fuel consumption is fairly dreadful, and only considered acceptible if you were to maybe compare it to a 6.0 V12 petrol in a near 3 tonne SUV.
I'd doubt the big Audi acts as much of a halo car in the way an R8 or RS model does either, and can't really see it promoting its Le Mans racers despite it sharing a supposedly similar engine. Besides, the Le Mans stuff is meant to promote the road car range, not the other way around.
The question why is only answered with "because we can."
The only big engined 4x4 I'd consider is the original G-Wagen AMG model.
