I wasn't thinking at all about situations that begin at a disabled vehicle. But vehicle or no vehicle an individual in a survival situation is fundamentally different then an army with solid logistical support which can evacuate casualties, bring in re-enforcements or bring in supplies that may or may not have been in the initial plan. We don't have that option. No casevac, no cold weather clothing if we didn't pack it. As you point out though, if you start from a vehicle the difference is far less pronounced, you don't have to strike as delicate balance between carrying everything you need and not leaving a heavy pack at home. Your car can carry your heavy pack it just can't get you home or to a hospital.