Start with a few safety items, including a first aid kit, flares or reflective hazard triangles and a flashlight with extra batteries still in their original packing.
Prepare for a flat tire with a foam tire sealant or a DC-powered air compressor. Make sure in advance you know how to use these items.
Keep tools, jumper cables and assorted fuses on hand so you or a passing motorist can try to solve mechanical problems. Vise grips, screwdrivers, an adjustable wrench and pliers are good versatile tools. Duct tape, cotton gloves and clean rags may come in handy.
Identify tools or items in your emergency kit which can be used to defend yourself. You may choose to supplement your emergency kit with a defensive weapon such as pepper spray.
Carry extra coolant in case your car overheats or has a leak.
Bring bottled water--an absolute necessity for your survival in the desert. Stay well hydrated throughout the journey so you can better handle an emergency.
Stow everything in a duffle bag in the trunk.