From what I've seen, the consensus of opinion over the last 20 years seems to point at Subie's QC going down, and Audi's coming up. If the trend lasts another 20 years, they might meet in the middle... but that's just opinion.
I think the proof can be found cruising the parking lots. Look at the age of the cars you see, ask owners how many miles they have on the clock. German cars have a reputation for "quality" that's not borne out IME by seeing too many 15 year old specimens with a quarter million miles on them (and most of them seem to be M-Bs.) I don't agree with everything Subaru's doing to their cars, their customer service MAY lack and IMO their parts network definitely DOES, but dollar for dollar, I think Subie still offers a lot more than my Teutonic forebearers have provided.
Rick