Blenheim Palace will play host to Coys of Kensington's latest sale on June 29, with Princess Diana's 1994 Audi convertible as the star lot.
The car, owned by Princess Diana and photographed carrying members of the British royalty several times, will sell with a modest £20,000-25,000 ($31,010-38,763).
This estimate is likely to be exceeded come sale day, with a Rolls Royce used by the People's Princess selling for $122,322 in an eBay charity auction in November 2012.
"This is an extraordinary opportunity to own a piece of Royal History. We have put a guide price on the car of between £20,000 and £25,000 but we have no idea what it will go for," commented Coys' managing director Chris Routledge, who also mentioned that the auction house have already received interest from America.
The car was photographed with Diana at the wheel in 1994, along with the young Prince Harry and Prince William. It was during this time that she was separated from Prince Charles, ahead of their divorce in 1996.
Coys have stated that the car will be displayed at The Grange Hotel in London's St Pauls prior to the sale, with visitor able to leave a sealed bid. They are also planning a competition in which the lucky winner will be driven to the auction in the car and provided with lunch.
This isn't the only royal ride to have sold at auction, with Queen Elizabeth II's converted Land Rover selling for £28,380 ($47,470) in November 2012 and Prince Charles' 1994 Aston Martin Virage Volante making £119,100 ($184,669) at Bonhams in May 2012.