Build A Sand Rail Game How To Build Roll Cage?

How to build roll cage? - build a sand rail game

Hey, Im Going to be buying and building a railway in the sand .. Sand car / buggy from a Type 1 VW Beatle and want to know what the size of metal is required, and where can I buy it .. The study must also be .. I am a part of the meeting .. but I need the size of the pipe. and where can I get it ..