A German court has ruled that the 1937 Mercedes-Benz 500K Special Roadster  purchased by Dutch collector Frans van Haren in 2011 was illegally liberated from Germany as a “spoil of war,” and that the descendants of the original owner have a legitimate claim to ownership of the car.

Van Haren purchased the car, one of 29 examples remaining in the world, from RM Auctions for a sum of $3.767 million. That was well-below the pre-auction estimate of $4 to $5 million, and the car’s undocumented history until the 1970s likely made many collectors wary of bidding.

The Dutch collector’s troubles began when he opted to display his purchase at Essen, Germany’s, Techno Classica show last March. Acting on behalf of the Pyrm family, the car’s original owners, German police seized the rare Mercedes-Benz under court order.

What happens next, as Bloomberg explains, is up to the German courts, but the Pyrm family is already marking this as a victory. In the words of Alexander Martius, the family’s attorney, “We think the decision is right and it’s an important step toward restitution. I am extraordinarily happy for the Pyrm family.”

Martius’ next step will be to file suit for the car’s return to his clients, which seems likely given the court’s actions to date.

While details on the car’s disappearance from Germany are vague, it appears that the Mercedes-Benz went missing while U.S. soldiers were occupying Prym’s estate in the closing days of World War II. The estate’s caretaker noted the car’s disappearance after retuning from a few days away, but the car was never found.

There’s legal precedence for returning spoils of war to original owners. In 2009, a sixteenth-century book worth an estimated $600,000 was seized from a collector and returned to a museum in Stuttgart, Germany.

That particular decision came from a New York court, not a German one, so it’s unlikely that a German court will side with anyone other than the original owners of the missing Mercedes roadster.

Where does that leave van Haren? That’s up to his legal team, but we suppose the short answer is $3.8 million poorer and much, much wiser.