For some reason...???
...Starting to shop for a used 2003-2006 BMW M3...which year is the best, and do they brake down alot??
The years you listed , all are the same body style/chassis, the E46. Find one that was maintained, a clean car fax, one owner, and while they don't break down, you will have to do some upkeep, especially if it has 100K miles or more. Figure $2-$3K annual maintenance costs. Thought not M3 specific, check out this link....http://www.bimmerfest.com/wiki/index.php? title=BMW_E46