My WP failure was actually the seal and not the impeller. That still looked fine.

2002 X5 280,500 miles
2004 325i 120,000 miles

I`m just replacing my water pump because I have 214000 km on it, and I have to take the fan off to replace the thermostat, so I figured I should do the wp at the same time ,whats an extra couple of bolts.also I am replacing the plastic wp pulley to aluminum.

Mine is 10 years old. If there still a lifetime parts warranty on certain OE parts in the US I would like to know about it.

all parts at fcp are life time.
https://www.fcpeuro.com/page/lifetime-guarantee

Two different BMW techs posted here on the lifetime BMW parts warranty, both are mentioned in the first link I posted. It is not on your original factory installed part, but rather the replacement. I suspect it only applies if the dealer installs it, otherwise it would be two years.

The list of covered OE parts was limited to starters, alternators, water pumps, struts, and maybe some others.

I don't know if the program still exists in the same form. Y'all are in a different country ;)

You are taking me back now. I recall that discussion. Someone posted a picture of an aftermarket metal impeller and said it would be better based on the material used. The construction details in the photo, and the flat vanes vs the curved vanes, cast doubt on that assertion. I think we got into a cavitation discussion.