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A car that was once owned by Princess Diana -- and used to shuttle her two young sons around in -- is about to be up for auction.

It's estimated that the teal green convertible Audi Cabriolet will go for about $70,000. The car that served as Prince William and Prince Harry's childhood carriage still has the same L449 TRP license plate that was on it when Diana owned it.

Diana bought the Audi in London in 1994 three years before she tragically died and is believed to have only driven the car about 4,000 miles. Diana often switched cars to attempt to throw off the paparazzi since they often followed her every move.

The Audi is just one of many iconic cars up for grabs at the "Jewels in the Crown" on Nov. 12 and 13 by Silverstone Auctions. Also there is a Bentley once owned by Queen Elizabeth II.

According to the auction house, the Queen's former car, Bentley Mulsanne, features several security features, including front and rear blue flashing lights, Kevlar-reinforced tires and armor protection and glass.

It was reportedly made especially for the Queen for her 2012 Diamond Jubilee tour of Great Britain. The auction house believes this car will sell for upwards of $300,000, as it's one-of-a-kind. In addition to the security features, the Bentley is also fitted with walnut burr veneered picnic tables, door panels and rear quarter vanity lights and the walnut veneered waist-rails featured inlaid Royal crests.

A 2005 Rolls-Royce Phantom first owned by Sir Elton John will also be auctioned off, and should sell for upwards of $200,000.

"It's an honor for Silverstone Auctions to offer cars with such amazing provenance, cars that belonged to HM The Queen, as well as being owned by some of the most influential personalities of the 20th century," Nick Whale, managing director of Silverstone Auctions, said in a press release. "We anticipate a huge amount of interest in these cars from across the globe. These cars have been wonderfully cared for over their lifetimes and we look forward to finding them new homes."