Haven't seen mention yet of a seatbelt cutter or glass breaker within reach.
In cab:
Spare hats, eyepro, earpro, binos
Weapons, spare mags, couple boxes of range 9mm
Targets, stapler
Small fixed blade knife with glass breaker attached to a seatbelt cutter
Small bag under rear seat with fuses, lamps, hot hands, small toolkit
Bushcraft knife, mostly keep a KA-BAR Becker BK2 under the back seat
Hatchet
Fire extinguishers
flashlights, batterys
First aid kit
IFAK including CAT and shears, extra quick clot pack (in every vehicle and my travel backpack)
Trailer plug adapters
tire gauges
Gloves
Water bottles in every door
Battery jump pack
Colorado mandatory butt wipe
One meelion keys for all the locks on everything
Toolbox
Assorted recovery gear, straps, chains, clevis, etc.
ratchet straps, bungee cords, 'biners,
flares
emergency triangle kit
tools
torque wrench
spare bearings for trailers
grease gun in plastic bag
one arm clay thrower
DEF filler tube
bottles of XPD
spare oil and fuel filters
funnels
rags
large pin tent stakes, hammer/trencher
SOG kit with axe, trenching tool, machete
I'm sure I'm forgetting a few things that get stashed and forgotten until needed and I dig around mumbling, WTF did I put that?