A mother’s simple request for friends to drive by and honk for her son’s 21st birthday evolved into 90-minute parade with marching bands, dance groups, motorcycles and firefighting equipment. Mathew Robinette’s autism, cerebral palsy and other disabilities have left him unable to speak but he reacted to Saturday’s turnout in Anderson with smiles, laughs and joyful exclamations from his wheelchair. Kim Davis-Robinette says her son loves loud noises and sirens.