Can't edit my earlier post so, just thought I'd share a 504 oil that is very affordable here down under (where we get ripped another hole for everything) as in Mobil 1 & Castrol edge oils are the same prices. I found Shell Helix Ultra ECT 0W30 with a 504 rating, cheaper than the other brands...
Concerning VAG DI engines. Many of us have been round n round concerning oil properties right? Great learning curve but, tedious all the same. HTHS, Ash level, Visc, oil drain duration etc etc ad nauseam!
However my oily friends, I found a single page, concise write up on the oil prpoerties...