The U.S. and Japan have had the Nissan GT-R on the street for the better part of a year already, but Europe continues to wait - the first cars won't be delivered until Q1 2009. But that hasn't stopped the tuners from moving forward with tuning kits for the Japanese supercar killer.

With AWD, an upgraded 478hp (356kW) twin-turbo V6 and improvements honed in the U.S. and Japanese markets, the European model will already be a step above the 'Series I' GT-R. The Germans at the COBRA N+ division of Cobra Technology & Lifestyle have decided to take the car to the next step.

Increasing turbo boost by just 2.2psi (0.15bar), tuning the ECU and adding a pair of sport air filters is enough to secure a 543hp (405kW) and 502lb-ft (680Nm) rating. A full exhaust with high-flow cats and stainless steel tubing is currently under development, and could offer even more power thanks to reduced backpressure.

Handling modifications include a custom set of adjustable coil-overs, three piece 21in COBRA N+ alloy wheels, and 15.9in (405mm) brake discs at the front end.

A fully customized exterior is also part of the package, with functional aero elements worked in to the front air dam and lip spoiler, designed to reduce aerodynamic lift and increase airflow. An upgraded rear diffuser and rear spoiler also aid airflow and downforce, while a custom decal kit pays special attention to the unique lines of the GT-R.

No custom car would be complete without a modified interior, and the COBRA N+ delivers with hand-sewn upholstery of leather and alcantara, carbon fiber race seats and six-point harnesses with a full roll cage.

COBRA N+ is planning to have the kit ready for sale when the GT-R arrives for retail sale in early 2009.