Will Smith and Margot Robbie

LOS ANGELES -- While filming "Focus," Will Smith and rest of the movie’s cast learned a few things about the sights, sounds and speeds of Verizon IndyCar Series cars.

As they made their way into the TCL Chinese Theatre for the film’s premiere Feb. 24, the stars shared their memories of the days at NOLA Motorsports Park when Verizon IndyCar Series team owner Bryan Herta and driver Carlos Munoz took race cars onto the road course as cameras rolled.

“The Indy cars were fantastic,” said Smith, who plays a con man perpetrating a racing double-cross in the movie.

Director John Requa said the Verizon IndyCar Series "jumped to mind" when reading the screenplay.

“IndyCar is just the fastest American racing car. It’s an exciting world and it’s an exciting sport and we hope people appreciate it when they come away from it,” he said.

Veteran actor Gerald McRaney was impressed by the sounds of the IndyCars on location in Louisiana.

“There’s no sound like that, that high-pitched whine when they are topping out or when they are gearing down to take a curve … and it’s a beautiful sound,” said McRaney. “There are no microphones that can really capture that sound – (for example) you can hear a record of Pavarotti, but it’s not the same as being in the opera.”

Smith’s trainer, Darrell Foster, got a ride in the Indy Racing Experience two-seat IndyCar during filming.

“It was exhilarating,” said Foster, who also trained world champion boxer Sugar Ray Leonard. “We hit 150 and … you can’t get the perception of it from TV.”

Foster uses IndyCar racing analogies when he trains clients.

“You would not put an IndyCar on the track with clogged fuel injectors or grimy oil, so I use the same analogy for the human body,” he said.

Alfonso Ribeiro, who attended premiere to support Smith who he worked with on the 1990s sitcom "The Fresh Prince of Bel-Air," isn’t a stranger to IndyCar. He's a friend of driver Marco Andretti and Herta and attended the 2014 season finale at Auto Club Speedway. The most recent winner of "Dancing With the Stars" plans to attend the Toyota Grand Prix of Long Beach on April 19.

“It’s going to be cool. It’s great to see an IndyCar, you know,” he said. “Seeing Bryan Herta’s cars in the (movie) is going to be awesome.”