In my first aide kit I have in my car some 2x2's, 4x4's, 3 abd pads, band aids, steristrips, tape, an ace wrap, kerlix, antibx ointment, a sling, several masks, gloves, a suture needle and silk. The only med I carry is benadryl.
Then I have a little travel bag with water, some food stuffs like crackers, chocolate bars, hard candies, one spare change of clothing(old sweat pants, sweat shirt, socks), a blanket, flashlight, radio and spare batteries and a swiss army knife. Also jumper cables. I love the little radio. It can pick up radio stations and tv stations and is small in size. All this goes into an old backpack, so I can be mobile if needed. In the winter I throw a bag of kitty litter in the trunk, in case I get stuck in the snow. The kitty litter works great as a way to get some traction.
I started it for earthquake readiness in Cali. In the midwest I have it in case of tornadoes.
One kit in the car, one in the basement. The one in my basement has more stuff. I even keep a small bag of dog food for my best friend. Which reminds me, I should be switching out some of the items, the food and water.