Since becoming a standalone automaker, Polestar has proven to be a serious player in the auto industry. The Polestar 1 is a superb-looking hybrid sedan that makes tackling the Nurburgring look easy, while the electric Polestar 2 is a worthy rival to the Tesla Model 3.

But this doesn't mean Polestar's long-standing collaboration with Volvo is ending. Our spies have been sent photos from a Volvo fan of Polestar testing a mysterious new model outside the Hallered Proving Ground near Gothenburg, Sweden, that appears to be a camouflaged Volvo P1800 with some design modifications.

Compared to the original Volvo P1800, the fenders are wider, as are the wheels and tires, while the lower front fascia also looks different to the original. Another crucial change is that this new Volvo P1800 doesn't have any exhaust pipes, so it could have a fully electric powertrain. What exactly is Polestar cooking up here?

Next year marks the 60th anniversary of the Volvo P1800, so Polestar could be working on special one-off electric restomod project to celebrate Volvo's iconic coupe. According to our source, the car is registered as a red 1964 Volvo P18335 VD and is owned by Mattias Evensson, who has been the head of engine development at Volvo's Cyan Racing division since 2007.

The car was also previously owned by Jonas Christian Dahl, who became the owner of Polestar in 2004 and is the current CEO of Cyan Racing. Before Dahl acquired it, the car belonged to Cyan Racing.

Nothing is official yet, but we're very intrigued to see what Polestar is plotting. An electric restomod seems like a fitting modern tribute to the Volvo P1800, which has been out of production since the 1970s. If it's being developed to celebrate the sports coupe's 60th anniversary, we may have to wait until 2021 for an official reveal.