A host of next-generation Mercedes-AMG GT prototypes were spotted around and in the Nurburgring, suggesting the automaker could be nearing the final stages of development.

CarSpyMedia caught the upcoming sports car in three colors, all appearing to be powered by a V8 engine.

The new AMG GT will have much in common with the Mercedes-AMG SL, including the engine and an interior with rear seats. Mercedes will likely use the two V8 options currently available for the SL, which could be the main differentiator between the red, blue, and silver cars we see on track.

Both engine options are the well-known 4.0-liter twin-turbocharged V8 but in different states of tune. The 55 produces 469 horsepower and 516 lb-ft of torque, while the 63 ups the output to 577 hp and 590 lb-ft.

Although not seen thrashing around the German track, the highly-anticipated AMG GT 63 S E Performance coupe also makes an appearance in the video. It can be identified by the mandatory yellow warning sticker and dual exhaust pipes. The more traditionally powered models have a quad-pipe setup, which makes a lovely racket.

As we've reported before, Mercedes-Benz will offer the new GT in top-spec 63 S E Performance guise. The mighty plug-in hybrid based around the 4.0 V8 first made its debut in the AMG GT 4-Door.

In the 4-Door, it produces 831 hp and 1,084 lb-ft of torque, making it the most potent AMG powertrain ever produced.

With the camouflage wraps slowly dropping with each sighting, we expect Mercedes-Benz to unveil the new AMG GT soon. A leaked internal document revealed that it might reach showrooms as early as October this year.

Thanks to those rear seats and a host of comfort and driving-related updates, it's expected to be a more fitting rival to the Porsche 911. It certainly looks like less of a handful than the outgoing car, but then again, we'd like to see it do a few wet laps, too.

Looking ahead in the calendar, the International Motor Show Germany (Munich) is scheduled for September, and that seems to be the most suitable platform to launch this new beast.