I'm not sure my list meets your weight addition requirement, because the last thing I'm worried about if I'm stuck/stranded is a couple hundred pounds of gear, but here goes.
My vehicles are well maintained, Which keeps me from working on them when I'm supposed to be hunting/scouting. Both are equipped with lockers front and rear, which has kept me from dragging out recovery gear more than a couple times. I still carry some parts and tools to get me out of trouble just in case the unforeseen mechanical issue happens. Also, I have a dedicated backpack in each vehicle with items similar to what you would find in a bug out bag, in case I can't get unstuck and have to wait for help. So far, I've only used items out of them for situations less severe. Handy to have along. Most items in it I'd have anyway out hunting, but not necessarily when I'm out scouting.
Dedicated tool kit for vehicle.
Spare belts, hoses and hose repair kits, 2 gallons pre mix coolant, 2 quarts of engine oil. The spare belts are take offs from regular maintenance, I replace them before they are un-serviceable, and rotate the last take offs into the vehicle as spares. For the diesel pickup, I also carry Power Service diesel fuel additive, in case a severe storm rolls in, or a refuel is necessary on the trip.
Permanently mounted winch and heavy duty winch bumper. Winch should be rated at 1.5X vehicle weight, or more.
Winch controller, leather gloves, a couple clevis/shackles. Mounting points for Clevis/shackles are incorporated in front bumper, for rear I use a receiver mount clevis/shackle anchor point.
2-3" wide snatch strap, depending on vehicle weight.
(3" is in pickup, 2" in Jeep)
Tree saver strap.
High lift Jack, bumpers and rock rails capable of supporting lifting vehicle by them. Also carry a bottle Jack in pickup.
4 tire chains. Tire plug kit. Spare tire in good condition.
Air compressor (Viar in Jeep Rubicon, ARB air locker compressor in truck, with hoses and fittings to reach and air all tires).