Mattie's Inventions

Mattie has been  thinking of new inventions to help our environment~ He wants to adapt our speed racer sleds to run on veggie oil; but he also wants them to have explosive capabilities.  "Blasters"  would be an option for the military (or family members promising to be careful with the blasters).  He also wants them "to be able to turn into anything, " so that, if one should come upon a boulder whilst riding their speed racer they could push a button, turn it into a bulldozer and "voila"....boulder problem solv-ed.  He hopes that he can sell a lot of these so he can help the environment.