The silver Ford classic that Prince Charles gave to Princess Diana as an engagement gift in May 1981 will be up for auction at Reeman Dansie's Royalty, Antiques and Fine Art Sale in Essex on June 29.

The Ford Escort Ghia Saloon is estimated to fetch between £30,000 and £40,000 given its pristine condition. Its previous owner, a "great admirer" of the late Princess of Wales, safely stowed it away in a garage for the past 20 years.

Thus, the car still has its original registration and license plate number WEV 297W, and original paintwork and upholstery. It still also has the silver frog mascot on the hood, which was a copy of the wedding gift Princess Diana received from her sister Lady Sarah Spencer, to remind her of the fairy tale of the frog prince. The late royal only clocked in 83,000 miles when she drove the car before it was sold to a private owner in August 1982. That number has not changed to this day.

"The car has been dry stored for quite a few years. This is really nice because keeping it stored in a dry barn or garage has kept it in a really nice condition," Lewis Rabett from Reeman Dansie auctioneers told People.

"Escorts of that age weren't like modern cars with really good galvanizing and rust proofing, so a lot of them have just rusted away. Now, 40 years later, you don't tend to find Escorts at all, let alone ones with the provenance of this car," he added as he made note of the 1980s Ford radio still intact which means "nobody has changed it and fitted a super modern thing, so it's just as Diana would have driven it."

Rabett shared that he has driven the car himself and called it "a lovely step back in time." He admitted that it was "very surreal to sit behind the wheel and think who would have been there at an early part" of Princess Diana's life when "she was young and before she went on to do all that she did in her unfortunately very short life." He added that the fact that the Ford Escort Ghia Saloon is in silver "makes a difference" because it is in a "very bright shade" that it "just really shines in the sunlight."

Princess Diana
24 February 1981: Lady Diana Spencer reveals her sapphire and diamond engagement ring as she and Prince Charles pose for photos in the grounds of Buckingham Palace following the announcement of their engagement Tim Graham/Getty Images