Good stuff. In addition I like to have-

a CPR mask
rubber coated work gloves for protection from sharp metal etc.
wool blanket for warmth, cushioning, or an improvised stretcher
tape (duct or otherwise) for holding on the dressings
headlight


in a pickup truck I have a sheet of plywood that is both bed liner
and backboard (cut in pieces so the backboard is easy to get out.
I used this when a little kids dog was hit and we had to move it
out of the road.