Even though I've been away from it for a while, here's my experience as a former Audi service advisor.
When new, particularly leased, people don't really pay attention to anything unless a light comes on. So with a 10,000 mile oil change interval, they'd roll in the door after 6-7K with "my oil light is on." We'd add sometimes 2+ quarts and send them on their way until they're due for that 10K service. They never so much as opened the hood to even see if there's an engine under it lol. Happened with other makes I worked for as well. So if you find a "nice" used version of these cars, it was most likely a lease turn-in and treated this way. Unless these - and most ANY late model car in my opinion - cars you're looking at are still under factory warranty or at least CPO'd, be prepared for $$.
If that car is burning 1 quart every 100 miles, you've got some serious issues. My first car was a handed-down 77 Chevy Vega (yes I'm old lol) and at 90,000 miles it was burning a quart every 900 miles lol. Industry standard usually is 1 quart per 1000 miles is "acceptable". Exceptions were the rotary engine and one of those other German brands that I worked for - 1 liter per 1000KM (1 quart every 620 miles) was "acceptable."