A black 1999 Mercedes-Benz SLK230, which was bought new by Dannii Minogue and subsequently passed onto her sister, Kylie (pictured top right), is to be sold by Bonhams.
The car will appear as part of its annual Goodwood Festival of Speed sale on July 2, with part of the proceeds to be donated to charity.
The celebrated Australian sisters have been the car's only two owners. It is in fabulous condition having covered just 19,000 miles from new. The pre-sale estimate is £8,000-12,000.
Kylie - recently declared by researchers to be "the most powerful celebrity in Britain" - releases her eleventh studio album, Aphrodite, in July.
Dannii is a judge on hugely successful shows The X Factor and Australia's Got Talent, produced by pop music impresario Simon Cowell.
"We are delighted to have been appointed by the Minogue family to offer the Mercedes-Benz," said James Knight, Head of Bonhams Motoring Department.
"It has all the right ingredients - good colour, low mileage and a fantastic provenance.
"Kylie and Dannii have a tremendous and far-reaching fan base and I can see it appealing to many people who want the same experience that they both shared."