Always buckle your kids into safety seats, no matter how slowly or how far you intend to go.
My mom, sister-in-law, and all my nieces and nephew were riding just a few miles to my aunt's house last weekend when they were hit by another car. My sister-in-law got a pretty big bump, but all the kids were perfectly fine, thanks in no small part to their car seats. My oldest niece (who will be five in a week) was frustrated when people kept trying to talk to her, making sure all the girls were alert.
My youngest niece finally said, "I don't want to talk about it anymore because it scares me." Yes indeed, scary.