Misc spare parts, small, nuts, bolts, washers,carb cleaner, gasket material, razor blades ,
Ign cap, rotor, wires, plugs, epoxy,carb gaskets and parts,drain pan, funnel, rags, valve train repair tools and spares, hose, clamps, torch, tie wraps, epoxy,sand paper,wiring kit and wire, small wiring parts,electrical test equipment, tow straps, cell phone, other racers numbers in case you need a tow, check tow vehicle spare tires, tire change equipment,,,,,,,

Contributed by Eric with the Arrow. They make the trailer ramp cables easily visible. Although I don't bring them I thought it may be a good addition to the list. As I said, this list was compiled from other posts by many members of the same nature here, I just used my own 'shorthand' abbreviations.