One of my favorite toys as a kit was the "Krazy Kar" (see photo below). One day I decided to build an adult sized "Krazy Kar" (see video above).
After using this Krazy Kar in the normal / usualy way, I decided to build a Giant Robot Costume on top of it. (see the costume here).
Below are links to the build-it-yourself plans:
Wheels are pneumatic and are "replacements" for a "garden cart".