The engineers over at McLaren are raking up the miles on their 720S hybrid test mules, with our spies catching another glimpse of the swirly-camo’d model while being driven on public roads in Europe. (Updated: 5/22/2019)

Just last week, McLaren unveiled the highly anticipated GT, but it’s far from the only new model in the pipeline.

As part of the company’s Track25 business plan, McLaren will introduce 18 new cars or derivatives by the end of 2025. A handful of those models have already been introduced – including the 600LT Spider, 720S Spider and Speedtail – but that still leaves a number of vehicles unaccounted for.

Now we’re getting a better idea of what to expect as a mysterious mule has been spotted undergoing testing in Europe. Based on the McLaren 720S, the car doesn’t look like anything special at first glance. However, the company dropped a few hints thanks to “Hybrid Prototype” badging on the side scoops and hybrid warning labels on the rear quarter glass.

Other than that, the model looks like a traditional 720S. This suggests McLaren engineers have figured out some clever packing solutions as they were able to fit the hybrid powertrain into the car without making any visible modifications.

Unfortunately, little else is known about the model. That being said, the fact that the mule is based on the 720S could suggest McLaren is working on a hybrid successor for the high-performance model.

Also Read: McLaren Will Launch 18 New Cars By 2025, Including P1 Successor

The news isn’t very surprising as McLaren has previously said 100 percent of their sportscar and supercar lineup will be hybrid by 2025. The company has also revealed it is working on a “lighter, superfast-charging, high-power battery system for performance applications.” This should enable future models to have “over 30 minutes of electric range” on race tracks.

That’s not much to go on, but the upcoming model will likely use a next-generation carbon fiber tub developed and manufactured at the new McLaren Composites Technology Center in the Sheffield. The facility opened last fall and promises to be a “world-leader in innovating lightweight carbon fiber and composites.” The center will begin building trial tubs this year and is slated to become fully operational in 2020.

Picture credits: CarPix & S. Baldauf/SB-Medien for Carscoops