EJ,
My great aunt, Arlene used to tell us not to hang any body parts out of the moving car but her excuse was that a "big truck would come by and rip it off". For YEARS I thought that's what happened to all those odd shoes and gloves on the side of the road. Scared the shit outta me the day I saw somebody's hat in the ditch! :-) Of course I never could figure out how the 'big truck' was going to pass us on the right (US) and take my arm/leg off...