Plastic for cooling sucks.

what about the plastic nipples on GM 3800 engines that would suddenly "blow" apart that screwed into the end of the manifold.... or the many plastic intake manifolds that would warp and leak..... those kinds of failures shouldn't be allowed to happen.... the pound and 1/2 they saved vs staying with aluminum (which never warped) would have never warped like the plastic ones..... talk about designs that were specifically designed TO fail.....
Ive replaced many Jeep radiators whose side radiator tanks suddenly decided to burst..... idiots.

My Buick has the supercharged 3800, 160k miles and those plastic coolant tubes haven't failed *yet*. Something on my to-do list for sure. I love those engines though, Chrysler never made anything comparable. Drives like a healthy V8 but gets 27 MPG on the highway.