What are the best performance upgrades for my Audi A4?

I am looking to enhance the performance of my Audi A4. I have already upgraded the exhaust and suspension, but I want more power. What are some recommended upgrades that I can make to my A4 to improve its overall performance?

The first and most important step to improving your Audi A4's performance is by upgrading to a performance air intake. This will increase airflow to your engine, resulting in more power and torque. Additionally, you can consider upgrading to a high-flow catalytic converter for even more gains in performance.