The Lamborghini Countach continues to explode in value. It's gone from poster car to a high-dollar collector car. Now two are set to cross the auction block, this time in the United Kingdom courtesy of Silverstone Auctions.

First up is an absolutely stunning example of the 1989 Lamborghini Countach 25th anniversary edition. For some, this is the Countach to have (I'll take the LP400 in either black or white please). Zonda creator Horacio Pagani is the man responsible for many of its lines, and it still takes on the visual cues of a spaceship brought down to Earth for high-speed exploratory runs.

This particular car was owned by Cleo Roberts. She was the wife of Carroll Shelby and quite a success in her own right. This afforded her the ability to buy the cars she dreamed of owning while growing up in London. Her Countach is a rare right-hand-drive example, and it's expected to fetch between $300,000 and $425,000.

1983 Lamborghini Countach 5000 S HR

1983 Lamborghini Countach 5000 S HR

Also scheduled to be offered in Silverstone is a rare 1983 Countach 5000 S. This one also has right-hand-drive, and it was owned by Prince Salman Bin Saud Bin Abdulaziz Al Saud of Saudi Arabia. This car spent some time in Saudi Arabia before heading back to the U.K., which is where it was originally purchased. Since then, the car has undergone an $85,000 restoration before being shipped off to a protected storage facility in Mallorca.

Like Cleo Roberts' Lamborghini, this Countach should fetch somewhere between $300,000 and $500,000.

The auction will take place on May 20 at the Silverstone Circuit.

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