What is the best modification for the Nissan GT-R?

I just bought a Nissan GT-R and I want to make some modifications to improve its performance and appearance. What modification would you recommend and why?

I would suggest adding a performance chip to enhance the engine's power and torque. This will give you a noticeable increase in performance and acceleration.

Invest in a high-quality exhaust system. It will not only increase the horsepower and torque, but also give your GT-R a deeper and more aggressive exhaust note.