I'm a huge 5'5" tall 145 lbs. so you have to use your head.
Smile and wave is the answer, if they do come back ( they won't ) tell 'em you thought they must know you shouting like that
Since in my area, Little Rock the amount of riders has increased tremendously in the last thirty years this is a lot smaller problem than it was.
Far less trivial is the fact that riders here are killed by drivers and never prosecuted.