Stuka covered all of them. I had an 02. Great car.

 

Find a good indy to do a complete PPI. Try to buy one with completely documented history. Stuka got most of it. You can unlock a secret menu in the OBD and run a check on the MAF's. Pinch the hoses that go into the plenum right at the front (oil cooler lines) if they are mushy you will need to replace them ASAP, not expensive to replace but expensive if you don't. Check for rust in the gas cap area. I am allowed to mention another site here? m5board.com has great resources for all this info. You should read the FAQ's before you buy. Also they have a very active forsale section you should check out.

Rob
02 E39 M5 Imola / Imola Black

 

I have an 03, put about 5K/ year on it. Really a great car. My problems have been with nav, replaced once, radio, replaced once (both under an extended warranty at about 5-6 years). Early on (year 1) I had a CEL, and drove home in LIMP mode, turned out a electronic fuel injector had failed.
Tires last me about 9000 miles (PS2's). Serviced once a year by dealer.
Great car for road trips, fast comfortable, discreet, even get about 24 mpg at 80.

 

Def one of the cars that a PPI is def required, the major issues on this car that can be wrong are not cheap at all....

I've owned three....and got lucky on two of them...the third was a doozy!!!

 

My '02 is in the shop and the list of repairs is beginning to mount. Most are routine (ie, brake pads and rotors, bleeding/replacing brake and transmission fluids, etc). I'm going to pick the car up when I get back in town later this week, I'll post the result and analysis of the maintenance some time this weekend.

*Some how my steering gear box is leaking, don't know how though. My father is the previous owner and I don't think his driving would have been the culprit. I've never tracked the car as I had my B5 S4 at the time and the car only has 45k miles. Working on the steering gear box is a lengthy and expensive process since they have to support the weight of the engine and bleed it for three hours. However, my local shop has informed me that they have never seen such a problem with the e39Ms...great