Maybe on the turbos but not on the bottom end. The 2.7l V6 has factory forged internals and 6 bolt mains. It's built to very tight tolerances and is pretty well known for lasting a long time, and making double the factory HP on stock internals. The biggest weakness comes in the factory turbos themselves and electrical issues. I never said my CEL isn't on. In fact it's on more than its not. I've got EGT sensors to replace, possibly an O2 sensor, and it might be about time to gut my pre-CATs. That'll also require me to modify the primary O2 sensor bungs in order to "trick" the ECM into thinking everything is fine.
To date my car has received 3 mechanical fan blades, 1 mechanical fan clutch, 1 engine snub mount, 1 set of Syncros, 1 clutch, 2 timing belts, 2 mechanical water pumps (part of t-belt service), 2 rear wheel bearings, 1 full set of rotors and pads, 1 set of spark plugs, 1 rear ABS sensor, 2 headlight housings (switched to E-code non-HID units to eliminate faulty HID's), 1 alternator, 1 electric water pump, 1 electric cooling fan, 4 sets of wipers, 1 license plate light assembly, 1 battery, 1 window regulator, 1 set if transmission mounts, 1 hazard switch, 1 ignition control module, 1 gauge cluster information display LCD, and I think that's about it. All over the course of 12yrs and 212,000 miles. I have all the maintenance records from the previous owner. It does need a windshield and tires, the damn thing loves to eat them up.
Audi tends to make very solid cars IMHO, but that's not to say they don't have their faults. Electronics are their weakness, although I haven't had too many issues there. Big difference too though is its an S4 that cost just under 50,000$ new. It's not some cheap little A4 that most anybody can afford brand new. I'm sure they paid a little more attention to QC (quality control)on it as such. It was also built in Germany, not Brazil or Mexico so that's even more reason for a higher level of QC over your run of the mill A4 or VW. Another thing is the people that can afford to buy a new S4 are typically more capable and willing to take it in for maintenance than those that buy an A4 or VW. I guarantee that I'm letting things slide on it more than the original owner I got it from. The same year A4 will probably have passed a lot more hands and be more neglected and beat down as such.
My wife is sold, she won't let me have the Audi back until I get her an A3 TDI or Q5.