I am currently looking to upsize from my A4 to an A6 and have pretty much agreed that I will be going for either a 2.5tdi, 2.7t, or 3.0v6, Quattro Sport from the early 2000's. I am aware of some of the potential engine faults with the 2.5 and the high repair costs of the 2.7, but am not sure on the 3.0V6, which i assume is the same alu block engine from the A4 of the same year?
What I'm also not sure of is though, is whether to go for a manual or auto. I will not be towing anything, and whilst smoking tyre starts from the lights or no longer my thing, relative performance still is. It seems that auto's are far more common with the manuals seeming to command a slight premium unless you shop about. Is there a huge difference between the auto/trip and the manual, and is fuel consumption and performance restricted going auto. Are gearboxes from either more susceptible to failure than the other?