So how would you determine that a belt is about to fail? I can understand that the dealership will stick to the manual since if it fails after they inspected and said you are good to go it would be the dealership's butt on the line. We are adults and can take the dealers advice or choose not to but then it is our fault if the decision turned out to be wrong.The only thing a BMW mechanic will tell you is you must change the belt when you have 24,000 miles. The criteria doesn't say to inspect it. It says to replace it. No ifs, ands or buts.