I hesitate to respond only because it will make me sound like a total and complete geek, but here goes.
C3PO was machine polished.
Yeah, yeah, everyone else remembers Princess Lea having the cinnamon roll hairdo, or Han Solo shouting "don't get cocky, kid" to Luke, or they can do a perfect imitation of Yoda or Darth Vader. Me? I remember C3PO getting machine polished.
Heh, I must have had Autopia in my blood long before Autopia ever existed!! :dance