I second this. I had to learn about jack stands the hard way. The jack tipped and my RS fell on my arm while changing my first tire and pinned my arm between the tire and wheel well. I got lucky and it just bruised the soft tissue around my elbow. It did put a quarter inch deep divet in the skin on the side of my elbow the size and shape of a bolt on the wheel well. Stayed there for months as a reminder before it healed completely.