Pads are RECOMMENDED and/or REQUIRED.
If your car is more “open” and your knees and elbows stick out, you may want pads. If you are wearing shorts instead of long pants, you will want pads. If you've ever been dragged behind a Power Wheels car by your teammate, you definitely want pads. (This is not recommended, the dragging part.)
$19-$26 for a set of knee, elbow, and wrist pads:
Also motorcycle full (upper) body armor is available for $42, and allows rolling on the concrete without pain unless you hit a curb.