On this week's episode of CNBC's "Jay Leno's Garage," four time IndyCar world champion Scott Dixon talks to Jay about his violent accident last May at the Indianapolis 500. When another driver lost control of his car and veered across the track into Dixon's path, Dixon's car went airborne, ricocheting off the track wall and spinning back onto the course upside down.

Dixon emerged from the wreckage unscathed and returned to competition a week later.

"You have bad memories where you've spun out or hit the wall or maybe had a big crash," Dixon tells Leno, "and those still linger in the back of your mind."

But what the greatest drivers do, he says, is block those memories out. "They think about just positive things. It's a trick of the trade, and some people do it a little better than others."

Accidents are not uncommon in IndyCar racing. In fact, the Indianapolis 500 is considered one of one of the most dangerous racing events in the world. As cars approach 240 mph speeds in their lightweight frames, the slightest contact with another driver can set them soaring.

Recent IndyCar models are designed to shred parts in the event of a crash and deflect energy away from the driver. But excess debris poses a threat to racers coming up behind an accident.