Senner Tuning’s transformation of the Audi TT which is now called the POWER TT comes with a range of accessories and also packs additional performance into the German 2+2.
By adding aftermarket performance parts like a power converter, a new valve-controlled exhaust system linked to an intercooler and a sports air filter and also by revising the engine electronics, the Senner Audi TT is now able to develop 430 HP from its 2.5-litre turbocharged unit.
On the visual side, the Senner Audi TT comes with a series of carbon fiber applications to the body, a lowered suspension and a set of alloys 20 inch in size, wrapped in Sport 255/30-20 tires. The interior of the Senner Audi TT has also received the carbon treatment with applications on the steering wheel, tachometer, door handles and center console. 
Senner Tuning press release :
POWER TT with 430 hp – by Senner Tuning AG
The finishing specialist Senner Tuning AG from Ingelheim near Mainz offers a wide range of accessories for the Audi TT RS, which clearly identify appearance and performance of the sports car.
The Audi TT RS is already configured as a powerful vehicle. But Senner Tuning found a large potential to make the POWER TT even more powerful. A newly programmed engine control unit, a power converter and a valve-controlled exhaust system with sport catalyst in conjunction with an intercooler and a sport air filter increase the power of the series up to 430 hp. For all TT engines, a sports exhaust system with tailpipes is also available by demand.
Senner Tuning assesses each TT individually, regardless of the engine. And Senner Tuning provides light alloy wheels as well. 9×20-inch rims of Varianza T1S type together with Sport 255/30-20 tires complete the outlook. In addition, a good road grip with the large-scale tire support surface and lowering sport suspension are provided.
Furthermore, the tuner adds a few small carbon applications for the body. The carbon package includes a carbon housing and a spoiler on the trunk lid. Senner also uses expensive carbon fibers in the interior – enhancement of the interior is also available on demand. This relates to the finishing of the sport steering wheel, tachometer, door handles and center console. 

Source: Senner Tuning