This comes from Jeff in Oklahoma
"(I remember an) episode featured a character named Tommy Speed. He was a racing car driver and he and his sister, TwinTails, are testing racing vehicles for a worldwide competition. Tommy enters the race, but I forget if the vehicle's electronic brain is damaged or sabotaged by a competitor the night before the race. Astro Boy had been assigned to be Tommy's bodyguard, but Dr. Elefun realizes that Astro Boy's electronic brain will have to be installed in the car so Tommy can enter the race. Just as Astro Boy is de-activated Dr. Elefun removes the activator tube), Tommy goes to bed. TwinTails says she is tired and also goes to bed. The door of the laboratory opens, and there is Tommy's sister. "What are you doing up so late?" Dr. Elefun asks. "I'm TwinTails, Tommy's sister," she says. "I have something to tell you..." The scene shifts to the next morning, and Tommy has started the race. No sooner has he gotten out of sight then there is Astro Boy, flying alongside him! He tells Tommy that TwinTails is a robot and donated her electronic brain to Tommy's car. I think Tommy is chased and overtaken by a rival and they start to dismantle the car; there was a dramatic scene when Tommy broke away from his captors, throwing his body over the remaining unit. "No! No! Not TwinTails' electronic brain!" I don't remember the ending." ...Whew!!! Thanks much Jeff!!

Tommy Speed and his car the Silver Comet
(in an image from an Astroboy coloring book which was made