What you need-
-A box
-A rubber band
-4 coasters
-2 skewers
-Sticky tape

Step 1 Get a skewer and put a coaster on one side then you put the skewer through the hole in the box.

Step 2 Put it though the box you put a coaster on the other side and then you repeat the process on the other wheels.

Step 3 Put sticky tape around the wheels to secure them.

Step 4 Hold the rubber band behind the box and t then you hold the other end of the rubber band in front of it and when you let go of the back of the rubber band it will start moving.