While we await the public debut of the brand-new GLA at Frankfurt, we have these images of Mercedes-Benz testing the high-performance variant of the compact crossover at the Nurburgring. The GLA45 AMG will share the CLA45 and A45's 2.0-liter turbo-four rated at 360 horsepower and 332 lb-ft of torque making it the most powerful production four-cylinder engine in the business. The camouflaged prototype boasts typical AMG trim such as bigger air intakes and a more aggressive spoiler, larger wheels and brakes as well as a quad exhaust.