"Funeral Ritual Instinct" by Vexen Crabtree (2002)
The Not a Donor Card has long been a good idea. When people die, their healthy organs can be used to save others, unless they carry a card to say they'd rather let others suffer. There is no humane reason to de facto deny others your own healthy organs, once you are dead. There should be European-wide legislation to make all of Europe a donate-by-default region.
If peoples' religious or cultural delusions lean them towards social malefaction, then, they can carry a "not a donor" card, to exempt themselves from the moral duty to help others. By allowing these exemptions, the scheme is more likely to be implemented. Then, later, we can remove this exemption. Only religious extremists and confused individuals will oppose it, once the scheme is seen as a success all over Europe, not just in Spain.