from memory, my little 1990 honda civic holds:

in the glove box:
-screw driver
-3" fixed blade knife
-flashlight + 2 sets batteries
-lighter
-kleenex + baby wipes
-sunglasses
-charger for cel phone
-bag of trail mix
-power bar
-bubble gum
-local map
-pre-paid phone card
-tire pressure gage
-keychain led
-compass
-charger for the kid's DS

ashtray + console:
-a ton of spare change
-couple of batteries
-bic
-lip balm
-rolaids
-tylenol

under the seats:
-seat belt cutter
-2Ls water
-extra hats + mitts + socks (wool)
-long wool scarf
-50 ft paracord
-chemical warmers
-baseball hats
-1/2 of toys r us

in the trunk:
-spare tire, cables
-jack, tire iron
-fix-a-flat
-flares
-work gloves
-shop towels
-tarp
-50 ft paracord
-collapsable shovel
-golf umberella
-sleeping bag
-sm tent + fly
-wool blanket
-kitty litter
-washer fluid + oil
-air compressor
-fire extinguisher
-H20 proof flaslight
-extra batties galore
-coffee can, candles, bic
-more water
-extra coats
-extra snowpants
-work gloves
-paper towel
-extra sunglasses
-fully loaded first aid kit
-sm lunch bag with instant drinks + thermos, mres + heaters, hard candy
-2 fully loaded hiking kits, ready for a few overnights in winter
-1 scout leader's pack with hot chocolate, thermosses, snacks, extra lanyards, extra flashlights, local maps, compass, radios, 1st aid + psk