All of me, why not take all of me?

As I'm coming up to 70, I have had to renew my driving licence. On the application form was an opportunity to register myself as an organ donor. I did so. But thinking about this, it seems to me that it should not be me making that decision, but my children. After all, if the question does arise, I shall be dead, so what do I care? Those who are left behind, on the other hand, may care very much. The problem, as I understand it, is that to be of any use, organs need to be removed as soon as possible after death, or better still, while the heart is still beating. This means that the body has to be rushed to an operating theatre immediately after death, or kept "alive" on a respirator. Either way, I can see this causing considerable distress to any close relatives who may be present. I think it should be their consent that should be looked for rather than mine. Equally, the current debate about everybody being considered as a donor unless they opt out should equally be considered from the point of view of those who will be left behind.