All cars depreciate, but the the German cars have been doing much better lately due to an increased demand for luxury vehicles and overall better reliability than say 10-15 years ago. While BMW's sales have dipped at the end of 2016, that's pretty much a general market trend of less car buying. Despite their new sales drop, BMW had quite a large increase in CPO sales. Interestingly the #1 selling brand in my home state of Connecticut ironically is BMW.
Depending on how you run the numbers and separate your segments, here are some of the top resale vehicles:
Time/Money Mag- Porsche Panamera, BMW M3, BMW 4-Series/3-coupe
Forbes- Mercedes CLA, Audi A5, Audi A6, Porsche Panamera, Audi Q7
Edmunds: BMW M3, Porsche Panamera, Porsche 911, Mercedes G550/G63, Mercedes Sprinter (why not throw it in?)
I agree though buying a 5 year old BMW or Mercedes or Audi with 80,000 miles is probably a very poor idea. Even if they are decently reliable repair and maintainence costs are astronomical and simply not worth it.
I have a 2009 BMW E60 535i xDrive sedan. My father bought it for me new and handed it down to me when it was roughly 4 years old and 80,000 miles I was graduating grad school. It's been a generally solid car over the past few years. I have around 125,000+ miles these days but only drive like 6 miles each way to work. The N54 engine is notorious for turbo issues but I've yet to experience a problem (knock on wood). The problem is not so much reliability, rather just thousands in yearly routine maintenance. But that's kinda the known cost associated with owning a German car beyond the warranty period.
Anyways, I'm well overdue for a new car. It's just frustrating because all the cars I had been looking at are about to come out with a new release shortly.