You might ask why keeping a board (strong piece of wood) in your car is important. Well, in case you ever have a flat tire, you will need something solid and even for the jack to stand on. Sometimes you might get a flat on soft ground and a board could be a lifesaver. Make sure the board is at a good thickness and 2x longer than the base of the jack for even balance. Having a board might be that one key element needed to get that car off the ground.