I keep mostly 'self-recovery' items in my van.

a small toolbox with standard metric tools (sockets are the cheap $10 set
from Kmart)
a good tow strap
jumper cables
a hydraulic bottle jack
a safety orange road vest
flares
GOOD 6-guage jumber cables
a box of spare parts (oil filter, dist cap, rotor, plugs, spark plug wires,
vaious sizes of hoses, an extra belt)
a compartment full of 'chemicals':  oil, break cleaner, cleaning supplies,
rain-x, tranny fluid, brake fluid, ps fluid, etc...)
a couple of MREs, pots, cups, a small campfire coffee pot, utensils, canned
foods & a tupperware container of 'serving pieces': plastic silverware,
napkins, spices, tea, coffee creamer, sugar packets, vacuum sealed coffee
sampler packs, etc...)
trashbags
fire extinquisher
squirrel bag (its an EMT's first aid kit)
all the screens for my Westy
rope, tie down staps
a mechanics jumpsoot (so I don't have to get my clothes dirty when I break
down by the side of the road)
a box of surgical gloves (for keeping my hands clean when working on the side
of the road)
a VERY GOOD flashlight

Gregg Carlen
85 Westy, 76 Goldwing, 51 Plymouth, 75 Mercedes, 69 Alcort...need more toys!