Nice thread. I've stolen some of the ideas offered by Lono/Ironraven (thanks guys!), and I just added to my usual car kit an expanded bag with bandage/trauma items.

I dug an old diaper bag out of the basement, and I filled it with items that will never expire. I basically emptied my home stash of extra items - gauze, bandage rolls, etc. - and arranged it in the bag.

So, it now has 8 quart-sized bags, each with a pair of nitriles, 4 4x4's, and an individually sealed 3-inch-wide roll of kling wrap, that can be handed out to other people. I plan to add more to these packs next time I make a big first aid order. The idea, as per Ironraven, is to have something you can hand off to other people.

The bag also contains other items I had on hand - a box of 5 sealed kling rolls (I found these on clearance for $2 each), an extra pair of EMT shears, several Kerlix super sponges, several rolls of Coban self-sticking wrap (I found 4-inch-wide rolls at Tractor Supply in the vet supplies aisle. I used a razor knife to split them in half through the cardboard center tube, so I have 2 2-inch-wide rolls for each original roll), a 20 ml syringe also from the vet aisle for wound irrigation, a couple triangular bandages, several rolls of tape, a new bag of diaper wipes, a 4 pairs of N95 dust masks in quart Ziploc bags, and several extra pairs of nitrile in smaller plastic bags.

I really like this idea of expanded capability that won't spill, leak or go past its expiration date.