Here in the UK, we have an opt-in (except on a new driving licence application, defaults in unless you tick a box IIRC) organ donor registry which will use any bits I'm willing to donate (the lot, if it's of any use to anyone. What do I need it for? I'm dead at this point 😂).

It does require me to either die close enough to a hospital, or die in such a way that my meatbag can be kept on support until they can strip it for parts though. A dead human doesn't stay viable as parts for very long, and our NHS is collapsing before our very eyes (as is intended by the vile vultures in power, but that's another story entirely...)