One of the things we learned in Iraq is that when a vehicle gets hit nothing gets out that isn't attached to you. Same applies for when the first clue that your rig is on fire is when you feel a burning sensation on the back of your neck. I suggest carrying as much gear as possible in your pockets and on your belt.
For when time allows a more orderly egress I include an empty large back pack. If I have to walk out I can gather up what I think I will need based on the current circumstances.
leo