This is a neat idea for a boys room that happens to love hot wheels. Not really hard to do, just takes a little time.
The first step is to decide how large you need the rack to be, depending on how many cars your child has. The pvc pipe will be 2 to 3 inches in diameter, and you need to mark each cut at 3&1/2 inches long. Using the saw of choice, make your cuts. A good idea after cutting, use a metal file and smooth the edges of each piece. A rotary tool will do this part also.
If you want to paint the pipe, this will be the next step. Each piece will need to be painted separately. My suggestion is not to paint, but it is up to you. After painted completely and clear coated, allow to dry. Cut a strip of yellow duck tape and wrap around one end of the pipe, do this with each piece of pipe. When finished, use a black permanent marker and make slanted stripes to resemble construction cautions.
This step will need to be done outside in a well ventilated area. Use the pvc cement and run a single strip of it down the outside of a piece of the pipe, place another piece side by side to the one with the cement, and hold in place for a few seconds, to allow glue to set. Be sure to place pipe pieces with all duck tape facing outside.
You will repeat the gluing step until you have a line of about 10 or 12 pieces glued together, depending on how big you want it to be. You will now start on the next level, this time, you will glue on the edges of the two pieces that the top piece will attach to. The way it will end up, will be a large triangle shape. This may help you to get an idea of how to stack the pipe pieces.
Once you have all the pieces connected, use the cement and connect hangers on the back in a way that they will be in the same line and on the far ends, to hold better. Hang on the wall and display all the hot wheels!
This is very versatile, you can use really large pvc pipe for dump trucks and large cars, just place on the floor, against a wall, and it makes a great storage for all the vehicles in the childs room.
Be cautious when using cement glue, it is hazardous to breathe