"If you read up on the ZHP VANOS, the seals come failed from the factory. By the time you get to 20,000 miles, they're completely shot. The rattle, for some reason, is more significant on the ZHP's.
Rajaie developed the rattle kit and seals, it should fix your problems."
http://forum.e46fanatics.com/showthread.php?t=806916
Don't have the rattle but was wondering what the failed seals may mean for our cars, and if its something that we should do something about.