Something else to consider. If you are storing stuff all over the car, trunk, under the seats, or in the hatch behind the passenger seat. It might be a good idea to put a inventory sheet in an appropriate place that lists where everything is. I'm sure you could find other things to include in the list too.

Yes to all except...professionally, I do not always have the choice to not go out in bad weather. And Eldest Recombinant DNA wouldn’t go out at all for about three months. I might say don’t go out in bad weather unnecessarily. Eldest has also been instructed that until temps are reliably over freezing to not park the car with less than a third of a tank of gas, and to fill up if leaving town regardless of the distance.

Yes. One concern is that Mrs. Magnet or Eldest might find themselves in some kind of difficulty and not know what it is that I have packed for them. Both have been subjected to training on what the kits contain but frankly neither of them are likely to remember.

It is worthwhile to involve the person likely to use this kit in the selection of its contents, rather than just handing it over. It is also a good idea to dust off the kit and use the components once in a while.

An inventory sheet is a good idea. It can also double as a checklist for regular inspections of the stuff.

Two points. First, remember that objects not securely locked in place will become missiles in a car accident and underseat under the drivers seat can impact the pedals even without an accident. Second, you might want to put in a comfortable set of walking shoes. I know you said your wife dresses for the weather, but this is occasionally overlooked.