My biggest fear would be to not do the preventative repair and have a failure only to have BMW only pay for a "portion" of the cost of replacement - making you pay labor or some other bogus charge (which would exceed the ~$750 cost I'm sure). Worse would be if you kept just passed 100k and then the failure happens and you're left holding the bag. Best thing to do is what you've done by ensuring the problem in your case is documented just in case something does happen. I would hate to have to pay for this repair when we all know it should be a BMW corporate responsibility, but being stranded in the middle of a blizzard sucks and is very unsafe as well!

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2001 X5 4.4i
2002 Honda S2000