Although there are many factors that enter into which car seat would be best for your grandchild (such as your own child's preference regarding the ease with which it attaches to the baby's stroller, or the weight of the car seat, in the event it needs to be carried - such as into an apartment or a doctor's office), I would begin my research of the car seat's safety at the websites for the National Highway Traffic Safety Administration (www.nhtsa.gov) and the Consumer Products Safety Commission (www.CPSC.gov).