I cant remember what Audi called for in terms of Oil change timing, but if they allowed you to stetch it out a bit, I would use the castrol 0w30 in a heartbeat in that car.
I wouldnt stray too far from what Audi recommends. Nice car BTW, just play within the rules.
It came with GC, the only 0w-30 to meet VW 502 spec.
Normal thin 30 weight will not do in that engine, except in the coldest cold.
I'd do a run of Auto-Rx and use 10w-40, unless it burns oil, maybe 15w-40 in summer unless you do mostly short trips.
Trip length and cliamte are the two factors. Any 5w-40 will do if you want synth oil, but it is definately not needed. The most common 5w-40 is Syntec, but I am not fond of it. Look for Shell Rotella T synth 5w-40...that's one of the best otc oils for that car, but really...dino 10w-40 like Pennzoil or Havoline is fine up to 5000-6000 miles.
AVK engine does have it's problems though. I would not skimp on the Auto-Rx.
If you like to use thinner oil, 5W20, in your new Audi then give it a try.
My '00 MB E430 had M1 0W40 (MB recommended) all its life until 90k miles, last spring I changed to PP 5W20 and the engine is so much quieter than with thicker oil, gas mileage increased about 3-5%. After about 5-6k miles the oil is so black I changed to Delo 15W40 and the engine is about as noisy as with M1 0W40 and gas mileage went down even worse than M1 0W40.
I changed oil last Dec to M1 0W20 and engine is quiet again and gas mileage went back up similar with PP 5W20.
Since most of the trips are less than 10 miles, the oil is rarely reach operating temperature so that thinner oil is better.