It is rather easy to make. The tools need is a file, drill, drill bits, an a Dremel with a cut off wheel.
Obviously, you will need a hot wheels car, a key, and some JB Weld.
1.You flip the car over and drill out the rivets holding it together and pull it apart.
2. trim the key/car to fit well together, take your time you can only do this once and don't get in the way of the wheels.
3. Thoroughly, glue in the key with JB weld then put some on the rivets so it wont come apart let it cure a few hours with the key supported, you will have an awesome key.