Should organ donation upon death be opt-in or opt-out?
I don't think you can assume someone's wishes. I think a person should have to explicitly opt in otherwise you might be going against their beliefs.
My estate has my rights.
Opt in. The dead can't vote.
If it were opt out then wouldn't it unlawful search and seizure?
Well, you are dead, so one could argue that you don't have any rights at that point.