Rocket-powered toy cars
Initially, I thought my sons would really enjoy this project idea. To be honest, I wouldn't let them go anywhere near this instructional video. For myself, however, I would love to try this out. Admittedly, this idea isn't something that would change the world. That said, why should it be? I suppose this is a sort of "duh" moment putting rocket boosters on a toy car. Looks like a lot of fun.