Oh gee. My Carry tool box is my aux tool box. Sometimes easier to pull stuff out.
Ok, 1/4” and 3/8” metric and sae sockets. Same for wrenches. Some 1/2” to fit wheel nuts. Pipe for breaker, vice grips, crescent, screw drivers, wire, side cutter, oil, wd40, metric and sae Allen wrenches, elec. tape, drain cleaner, torx bits, those other Torx bits whatever they are called, hammer, and a bunch of other stuff not used for ten or more years that might come in handy. Also a 100 foot tape measure, and latex gloves.
Then of course in the trunk a first aid kit, tick spray, spare key fob, bungees, rope, ratchet straps, army shovel, winter gear, paper towels, and a long pole with a pointed pick on the end. Not to mention my bug out bag and head light and batteries. Maps, cab and, insurance card, etc. phone charger, and I dunno what else. I don’t carry a spare computer anymore or a 2x4 since I got rid of the Buick.
In the other car, nothing except flash lights and shopping bags, since she would just call me anyway.
Story: maybe 25 years ago, I lost a cv joint in my other riv on the way to work. I made it to my garage stall at work but then all the ball bearing fell out. I decided I was just going to replace the axle after work. I made a list and called the wife. She was able to find and collect all of the stuff I thought I would need including air wrench. The building engineer had a compressor in the closet he let me use for getting the axle nut off. When she delivered my stuff we went to champion and picked up an axle. She left, I changed clothes and got to work. I think I was home by 9 after an hours drive. At any rate early enough to drop my core off at champion before they closed. I was amazed she was able to identify everything. Saved a tow, a day or two delay and a bunch of money.