Craig 
2000 BMW M5 Sedan 4dr Sedan
A few issues with the M5
 Well, I got the M5 in 2009 on a dealer trade with 160k.  The car runs a drives great.  A few problems for future owners to look out for.  Almost All E39 M5 have vanos knock.  It sounds like "rattles in a can" on start up.  BMW WANTED $4000 to change the VANOS  units.  Next, CARBON BUILD UP is a huge issue with this car.  If the previous owners did not take care of the car, there will be carbon deposits in the engine with will lead to a secondary airflow low code.  Sometimes the transmission would not shift into gears easily when it was colder outside. REAR LSD was also leaking.  NOTE: Trans fluid and LSD fluid is not lifetime fluid like BMW claims. CHANGE the fluids out.  Also car began to smoke