The car has also been spotted testing at the Nurburgring
The interior of the all-new TT features premium materials
Audi is using the circuit to benchmark performance
The motorised rear spoiler can be seen at the back of the TT
The wheel arches of this test mule appear more prominent
Subtle tweaks to the rear-end design of the TT are expected
This is the first time the next Audi TT has been seen
This disguised model was spotted testing on public roads in Germany and at the Nurburgring
The TT was seen performance testing with rivals in tow
Audi is benchmarking the new TT against the BMW Z4, Peugeot RCZ and Mercedes SLK
The car is likely to be launched in 2014 as a 2015 model
Engines will include the latest 1.8-litre and 2.0-litre petrols
A 2.0-litre diesel is also likely to feature in the engine line-up
A 2.5-litre engine will feature in a new TT RS in 2015
Audi has told Autocar it wants to mix elements of the old and new TTs
The TT is based on the VW Group's MQB platform
The platform allows for a shorter front overhang and a longer wheelbase
Both front and four-wheel-drive variants will be launched
Cylinder on Demand technology will feature in the petrol engine range
Audi's familiar rounded tail end can be seen here, as well as the motorised spoiler
Overall, the new TT looks slightly wider and longer than the current model
The third-generation Audi TT has been spotted for the first time, testing on public roads in Germany and at the Nurburgring.
Based on VW's MQB platform, which allows for a shorter front overhang and longer wheelbase, the next-generation TT will be launched with both front and four-wheel-drive variants.
Engines are likely to include the latest slimmed-down 1.8-litre and 2.0-litre EA888 petrol engines, which will include fuel-saving Cylinder on Demand technology. A mildly updated direct-injection 2.0-litre diesel will also be in the line-up. In 2015, a reworked version of the 2.5-litre five-cylinder engine will make its debut in a new high-performance TT RS.
A new six-corner grille, more angular headlights and a contoured clamshell bonnet can all be seen here, as well as the TT's standard rounded tail and motorised tail spoiler. The wheel arches of this test mule also appear to be more sculpted in appearence.
Previously, Audi told Autocar it wanted to mix elements of both the current TT and the original model into the new car. The company said the aim of the new TT would be to recapture some of the distinctiveness and impact of the first-generation model.
The new Audi TT is likely to launch towards the end of 2014 as an MY2015 car.