Tool and gear storage is such an individual thing: Put 10 carpenters in a room, and you’ll hear 23 1/2 different ways to set up a truck or trailer or site storage situation.
So it’s in that context I’ll throw you to a cluster of under-seat storage “panels” that are easier to see than describe, from a company known more in the off-roading zone than on the jobsite: BuiltRight Industries.
According to the website, "The BuiltRight Tech Panels provide mounting locations for all kinds of pouches, clips, straps, and gear." And they stick to carpeted surfaces you may find in your truck or vehicle. The large (8 by 15-1/2 inches) panel is $24 and it reportedly holds 15 to 20 pounds without peeling off.
It seems perfect for something you want instant access to that you also don’t want in your way at all times—like a first aid kit (check out Kirby Talks Safety here for some practical safety tips from his sites).
I can see them—with a little carpet mounted for a backer, or just some zippies—mounted inside a job box or on the wall of a service body truck or trailer to hold flashlights, screwdrivers, zip ties, chisels, and more.
I think the video is worth a look.