Copper Tank vs. Plastic Tank

What rad are you looking at? Could you post a link?
I thought I saw a plastic / aluminum one on rock auto for a Volare a while back.

I agree that it seems the plastic / aluminum ones cool great. All my new-ish cars have the factory ones (of course) and never get hot at all, no way. Seems like they are pretty light weight too.
I never seen one crack or fail in any way on my vehicles. But, good point already made, they probably wont last 30 years like the copper / brass ones do.