MORE ON THAT CAR SEATS AS CONTRACEPTION STUDY. “The obvious direct step is to eliminate any and all car seat requirements beyond two years of age, or at least within three or four years of age. The vast majority of the damage done by car seat mandates happens after age four and almost all of it happens after age three, whereas the vast majority of the safety benefits (or, more likely, all of them) happen by age two and certainly by age four.”