Kim Kardashian helped the PepsiMax Bullrun get off to a flying start at the weekend as she flaunted her curves in a figure-hugging jumpsuit.

The American reality star played pit-stop poser as she waved the green go flag at the beginning of the 1,700-mile race from New York to Texas.

The 28-year-old was up bright and early to wish 100 cars good luck as they started the seven-day rally from outside the Gansevoort Hotel in Manhattan.

After partying with the drivers the night before at SoHo House, Kim rose at 4am to get her hair and make-up done for her early photocall.

Showing off her famous derrière in the Lycra jumpsuit, Kim worked the crowd as she posed in her matching gloves and Christian Louboutin heels.

Hundreds of car fans gathered on Hudson Street to watch her lower the flag at the start of the rally.

On her Twitter microblogging page on Saturday morning, Kim wrote: 'I just dropped the flag for the Pepsi Max Bullrun Race. Good luck everyone.' Later that night, Kim flew back to her hometown of Los Angeles to attend a party at the Playboy mansion.

Kim is on good terms with Playboy boss Hugh Hefner after having posed naked for his magazine in 2007.
The Bullrun Race sees 100 cars, with both celebrity and non-famous drivers, spend seven days driving across America and stopping to party in a different city every night.

Participants pay $20,000 to enter the rally, which has a 'cops, cars and superstars' theme this year. Kim is now flying to South Africa with her sister Khloe and American football player boyfriend Reggie Bush for a charity trip. Hip hop producer and activist Russell Simmons arranged the trip for Kim with the Diamond Empowerment Fund, which aims to dig for ethical diamonds.