the reliability difference between e39 540i and an e34 m5 is very large. I read a past issue of "European Car" and they had an article all about buying a used e34. They said there are a lot of engine troubles and things can get very expensive. Even though the E34 M5 is a very amazing car that has a personality different from current M5s i would choose the E39 540i. When spending in between 20-40k i would want something fast, smooth yet reliable. add the sport package on the E39 and you have a car that can now hang with the E34 and be reliable at the same time.
~<>from MAXIMA's to BMW's<>~