The fully functioning Lotus Esprit submarine piloted by James Bond in The Spy Who Loved Me has been consigned by RM Auctions for its coming sale in London this September.

The car, which was nicknamed Wet Nellie on the set of the 1976 film, is based on a 1977 Series I Esprit and, according to RM, cost $100,000 to convert to submarine duty. Though other Esprits were used in the film, Nellie commanded the most screen time.

RM cites a curious post-production narrative for the car. After filming, the Esprit entered a storage unit in Long Island, New York, which had been paid upfront for a decade. But when subsequent billings went delinquent, the unit’s contents were offered in a blind auction, with no indication of what they might be. A local couple entered the winning bid (undisclosed by RM), and discovered the car under blankets when they opened the unit. After authentication, the vehicle was on show briefly at the Petersen Automotive Museum in Los Angeles, but has been rarely displayed publically since emerging from its Long Island exile.

RM did not reveal a pre-auction estimate for the Esprit, arguably the second most recognisable Bond car of all time, but Meghan McGrail, an RM spokeswoman, said the Esprit was expected to fetch over £500,000 ($760,000). The original Bond car, an Aston Martin DB5 used in 1964’s Goldfinger, was sold by the company for £2.9m at its London sale in 2010.

The Esprit will be offered without reserve at RM’s Battersea sale on 8 to 9 September.