As a long-term Cayenne owner I found the video below very interesting as it somewhat mirrors my experience. We bought our 2009 Cayenne in 2010. At the time it had 18,000 miles on it, came with the remainder of Porsche's factory warranty, and was CPO'd, as well. Since that time we've added over 140,000 miles for a grand total of 158k+ miles on the odometer. The vast majority of those miles have been trouble free and include numerous cross country road-trips with ourselves and the dogs.
When I think back on major maintenance issues, it's tough to come up with any. To date, the biggest item I can remember was having to replace the center support on the Cardan/Drive shaft (a common failure point for a lot of 1st and 2nd generation Cayennes). In fact, other than wear parts (brakes, rotors, tires, oil, plugs, filters, etc.) our Cayenne has been pretty much maintenance free. As we continue to accumulate miles on the Cayenne we've discussed the possibility of replacing it. However, it continues to run so well (and it still looks great) that it's hard to justify it.
After watching the video above, I've been inspired to create my own long-term ownership report for both my benefit and yours. We've seen a few S and Turbo model Cayennes with our kind of mileage still hanging on, but don't hear much about the V6 model with 150k + miles. What's the highest mileage Cayenne you know of?