What is the best performance upgrade for a Nissan 370Z?

I'm looking for ways to improve the performance of my Nissan 370Z. What upgrade would you recommend in terms of both cost and effectiveness?

One of the best performance upgrades for a Nissan 370Z is an aftermarket cold air intake. This will help improve airflow to the engine, resulting in increased horsepower and torque. As for cost, you can find good quality options for around $300.

Another effective performance upgrade is a cat-back exhaust system. This will not only increase power, but also give your Nissan 370Z a more aggressive sound. Prices can vary, but you can typically find a decent option for around $800.