If cars ever got sufficiently good at driving, one could make them much less crash-proof, thereby saving much more than $4B/yr in energy costs by making them li

If cars ever got sufficiently good at driving, one could make them much less crash-proof, thereby saving much more than $4B/yr in energy costs by making them lighter. They're much heavier than they were 30 years ago. Also, keep in mind that car crash victims on average have many more expected years of life ahead of them than the average heart attack victim. Also, we have a fairly clear path ahead of us for doing this, afaik the same can't be said about curing heart disease.