Our 1971 Beetle has an oil bath air cleaner and when you change the engine oil there is just the right amount left over from 3 quarts for the air cleaner. I don't find it to be a problem or inconvenience.

I've never cleaned or changed the oil in the air filter on my truck engine eek ........but then again it will be a few more months (years?) before it gets on the road grin

1946 Chevy Half Ton
('56 235, '86 T5, '79 Camaro Z28 rear end, working on the '85 Jaguar XJ6 IFS)
1976 Margay Panther X, MC91B