A millionaire with a Lamborghini, a truck driver in a stock Mustang and a slew of other racers in tricked-out rides push each other to new extremes

The qualifying rounds continue with the craziest obstacle yet and six new racers. The standout is a 21-year-old nicknamed the Baby-Faced Assassin.

The qualifying rounds continue with the craziest obstacle yet and six new racers. The standout is a 21-year-old nicknamed the Baby-Faced Assassin.

As the knockout round begins, the drivers must prove themselves on a newly redesigned course. But not everyone's car survives the chaos.

A new obstacle humbles the racers -- even one indomitable driver. Another contestant's overconfidence proves costly on the track.

With the competition down to eight drivers, the track designers crank up the difficulty with a new obstacle that turns out to be alarmingly dangerous.

A few old favorites return to the course for a series of head-to-head battles. The prize: a second chance at glory.

The course is downright diabolical. The margin for error is thinner than ever. The finale is nearly here. Go, drivers, go!

It all comes down to this. The top six drivers race through nine obstacles to determine the ultimate champion on four wheels.