A Horn
 

Who knows where to get a horn?

I know...
 

...that the Placebo Robot (the sub-bot) got its horn at an auto parts store on Perry Street in Pontiac (either Advance Auto or Autozone).

I didnt' know that a "horn" was on the list of approved materials.

Where can I get an electronic bubble making machine for our robot?

Thanks

Any item or material whose sole purpose and function is to decorate or identify the robot may be used (subject to proof of NON-Function by the officials). The placebo uses the horn as an identifying signal and as an auditory decoration: the inspectors approved it last year since it did not serve any useful function and was added to entertain the crowds. (it also gives the drivers someting to do since they have no other functioning mechanisms besides the drive train).