Representing the epitome of a niche model, the V8-powered compact crossover was spotted in prototype guise.

AMG never showed its love for the GLK, but that’s about to change with the new GLC destined to receive the mighty biturbo 4.0-liter V8. Addressing a very limited audience, the GLC 63 will be a high-performance compact crossover for those very few who will consider the 362-hp V6 GLC 43 not strong enough. Should you feel the need for more muscle, the V8 is expected to deliver 510 hp (375 kW) in the GLC 63 S.

To match the powerful heart, Mercedes-AMG is preparing a slightly more aggressive body compared to the “warm” GLC 43 and will also throw in some beefier brakes and larger wheels. More menacing exhaust tips and bigger vents will enable the GLC 63 to differentiate itself even further while the cabin will probably come with some extras as you would expect from a range-topping model.

There’s no word on how fast the crossover will be, but we are estimating a sprint to 60 mph (96 kph) in 4.1-4.2 seconds taking into account the “43” need 4.8 seconds. Top speed will likely be governed at 155 mph (250 kph), but in select markets there might be an optional kit bringing a less restrictive electronic limiter to enable a higher velocity.

Mercedes-AMG is expected to introduce the first-ever GLC 63 in October at the Paris Motor Show and put it on sale before the year’s end. It won’t have any real competitors for quite a while taking into account the BMW X3 M is not due until the end of 2017 or early 2018.

Gallery: Mercedes-AMG GLC 63 gets ready for V8 rumble