i live and work in fremont as well, although for the past 2 months or so i've been in seattle, so havent driven my car much (but so far ticking has not returned). Prestige BMW did give me the run around the first time i took the car there (i.e. they replaced ONLY the lifters, and the noise was even worse....even when i went to pick up my car!) i was told that its 'normal'. have never been to Fremont BMW; i was put off by their sales staff when i was shopping around.
and to the six sigma folks, yeah this shoud call for a black belt to look at the production processes for the affected parts. i'm assuming that the tolerances for those parts are not set high enough, hence the variation that makes it into the finished product. just a thought