This is the best look yet at Audi's new A7 Sportback that will be on sale in Europe by the end of the year.

Our colleagues at Carparazzi nabbed these images of the nearly-production ready prototype undergoing cold-weather testing. Based on the Sportback Concept revealed at the Detroit motor show last year the A7 is believed to ride on the same platform as the A6. But, as with the A5 Sportback, it is aimed to sit higher in the range and target the likes of the Mercedes-Benz CLS and even the Porsche Panamera and Aston Martin Rapide.

Given its high aims Audi has reportedly opted for some high-performance engine options including a 3.0-litre supercharged V6, new turbo V8 and even a V8 TDI capable of pumping out 800Nm. Naturally, Audi's quattro all-wheel-drive system is fitted to each model as is the seven-speed automatic gearbox.

It hasn't been a covert trip for the Audi test engineers, with the new S8 also spied by our friends at Carparazzi. Heinz and Fritz left all the duct tape and cardboard off their new high-performance S8 limo so as not to draw attention to the car. It looks just like a new A8, rather than the fire-breathing flagship model yet to be unveiled officially.

This particular car was nicely inconspicuous without the 'S' line body kit the production model will wear, as it underwent testing in wintry northern climes. Carparazzi has done it again and picked it as the S8 from its details. The lads and lasses of the long lenses observed the dinner-plated-sized disc rotors with calipers to match and a quad-tipped exhaust system.

Those four exhaust pipes support the rumour that the powerplant for the new model will be something special. According to Carparazzi, the S8's engine will be a 4.0-litre twin-turbo V8 when it arrives in the market.

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