Heart disease, cancer and chronic lower respiratory diseases are the top 3 leading causes of death in the USA, all regarded to be natural causes. Accidents are #4, and car crashes are included in that.
And if we exclude the age group to the people who use cars the most, like people in middle age driving around their family? I would guess most of the people in that car are not that likely to die from 1, 2 or 3 anytime soon.