There is very little that a fashion designer, a celebrity chef, Britain's greatest ever Olympian and a Sports Illustrated swimsuit model have in common, except for an extreme passion for motorsport and a burning desire to be crowned King or Queen of the Mazda6 Celebrity Challenge at Melbourne's Albert Park street circuit.

The full grid for the prestige celebrity showcase event was unveiled with actor Jonathon LaPaglia, flame haired songstress Sarah DeBono, former Australian cricketer Brad Hodge and TV presenter Scott McGregor taking up the final four spots in the celebrity race, which returns as a key support category of the 2013 Formula 1 Rolex Australian Grand Prix weekend entertainment.

Twenty-one Mazda6 Celebrity Challenge drivers will descend on the city from all corners of the globe from Sunday as they prepare to undergo three days of intensive CAMS (Confederation of Australian Motorsport) driver training at Sandown Racecourse, under the careful tutelage of V8 motorsport legend Mark Skaife.

Key match-ups for the race have already been identified including what is being touted as a pre-Ashes showdown between six-time Olympic Cycling Gold Medallist Sir Chris Hoy and Australia's London Olympics Golden Girl Anna Meares.

“Those involved in the Mazda6 Celebrity Challenge will be, by nature, quite competitive,” said Skaife. “They all want to do well, and it is our job to teach them how to stay safe and enjoy the experience while keeping them under control - which can be quite a challenge at times.”

The Mazda6 Celebrity Challenge at 2013 Formula 1 Rolex Australian Grand Prix is a core part of the launch activities for the All-New Mazda6, the Japanese manufacturer's new flagship family car. The race will also mark the first time that a diesel engine has been used.