Well, if that isn't a conundrum I don't know what is. So, I developed this jet pack to help him with his leaky gas issues.
Step 1: Spray plastic bottles with plastic primer (I used Krylon Fusion). Let dry.
Step 2: Spray bottles with your favorite silver spray paint (doesn't have to be plastic specific.) Let dry.
Step 3: Adhere bottles to a piece of cardboard, approximately the width of the bottles next to each other. Let dry.
Step 4: Use ribbon to create backpack-like straps. Adhere. (I used duct tape. That shiz works for everything!)
Step 5: Cut crepe paper strips to create flames. Glue the tops of the strips to another piece of crepe paper. Let dry.
Step 6: Accordion fold the top strip of the flames. Glue to the inside of the bottle tops (which are actually the bottom of the jetpack.) Let Dry.
Step 7: Run around the house making flying sounds with your mouth (or let your kid handle this step)
I used the 1.25 liter bottles of Coke products that can be found for about a buck at most big box stores. They have a cool shape, if you ask me. the straight cylinders of 2liter bottles work just as well.
I cut the tips of the crepe paper to make it look more like flames. Toddler Moose doesn't really appreciate that touch, but it makes me feel better about it.