The new car search for my ladyfriend has gone off the rails thanks to somebody's -- I won't name names -- recommendation of a CPO BMW, which led us to Z4s. They're an option in terms of purchase price, and I certainly like the 6yr/100k mi warranty. But what about after that? She'll eat up that mileage pretty quick with the driving she does - about 20-25k/yr.
Does anyone know what to expect from a high-miles Z4?

