sounds like what I carry in the truck besides the alternator relay, brake switch stopper, never had an issue with the relay on main power supply stuff, and I were slippers, which have built in brake switch stoppersWell......since you asked. I carry a 1/4" socket set with breaker bar, adj.wrench, pocket screwdrivers, 3xflashlights, 12V compressor, emergency jump box, tire pressure guage, fix-a-flat, lugnut wrench, jack, prybar, hammer, entrenching tool/ axe, OBD2 scan tool, complete set of spare fuses, an extra ignition coil, one of each spare bulb for all the exterior lighting, an extra alternator relay, brake switch stopper, bungee cords, paracord, a road flare, first aid kit, a Camillus ASEK, SIG P6, 83 rounds of 9mm, Bushmaster AR, and 170 rounds of .223 in my van.
But my Mini is way too pretty to put in the trunk, lol.
oh and guns and ammo...not legal here
back before I cared if I had to explain why there was a gun ridding around in my truck, I used to keep my mini in it for hunting on the way home from work.