An intriguing BMW M8 sporting a towering rear wing has been spied testing on the Nurburgring, triggering speculation that an even more extreme version could on the cards.

As it stands, the M8 family is topped out by the Competition in both Coupe and Convertible guise. The following prototype is based on the M8 Coupe Competition and looks identical to the road car currently on display at the Frankfurt Motor Show from every angle bar one: that wing that’s impossible to miss.

One plausible explanation is that BMW is working on a model to sit above the Competition; another, that this wing is simply going to be available in the M Performance list of options. If this is the case, then it is inevitable that BMW is also developing a series of other aerodynamic parts as well.

Also Read: BMW M8 Gran Coupe To Launch At November’s L.A. Auto Show

As it stands, available M8 variants are already pretty capable. Driving all four variants so far is a twin-turbocharged 4.4-liter V8 with 592 HP and 553 lb-ft (750 Nm) of torque in standard spec and 617 HP in the Competition. An advanced xDrive all-wheel drive system that offers 4WD, 4WD Sport and 2WD is standard, as is an eight-speed Steptronic transmission.

The M8 Competition comes complete with a small rear lip spoiler made from lightweight carbon fiber, but the fixed-wing of this prototype is certainly more eye-catching – not to mention downforce-inducing.

If it is indeed introduced as a performance part, don’t expect it to be cheap. Prices for the M8 Coupe start at $133,000 in the U.S. and rise to $142,500 for the M8 Convertible. The Competition is priced from $146,000 for the Coupe and $155,500 for the Convertible, so it’s an already expensive piece of kit and, thus, its performance-enhancing options should be on the same level.

Photo credits: CarPix for Carscoops