Winning a pair of Indy 500 races didn't go to the head of Helio Castroneves.

But his ex-fiancee, Aliette Vazquez, claims that the success this race car driver enjoyed on Dancing with the Stars drove his ego out of control.

Sources close to the couple told TMZ that the reason the couple split was simple: Helio went Hollywood! Reportedly, Castroneves' newfound "fame" was too much for his girlfriend of six years. As his popularity grew, so did the man's ego...

Dancing with the Stars champ Helio Castroneves dreams of Hollywood.

As a result, Aliette Vazquez hit the road, but is supposedly "over him," according to the insider. She was even spotted selling her jewelry line yesterday at the Biltmore Hotel in Miami. Take that, Julianne Hough!