Aston Martin is developing a one-off single-seat supercar.

A new video shows the automaker testing the car at a race track in Portugal.

Rumors suggest the car is for an American billionaire and will produce 1,200 horsepower.

Aston Martin is building something extreme. Back in April, a video posted to social media captured an insane-looking prototype from the automaker. It looked like a cross between a Formula 1 car and the Valkyrie, and a new video shows the automaker continuing to test the vehicle.

The Aston Martin is at the Algarve International Circuit in Portugal, lapping the track. The video from Ivo Matczak's Instagram account, ivomat_all_about_cars, captures the car’s glorious exhaust note, likely from a naturally aspirated V12.