I have a few questions regarding how I should go about upgrading my 2004 Audi A4 from stock to a 'speed demon'. What is the most effective method to go about adding HP and acceleration to my vehicle? Is this said method cost efficient? Where can I purchase the necessary parts in order to successfully upgrade my vehicle?

All responses are appreciated and will be considered! I'm not much of a car-tech savvy person, so estimated labor along with the necessary parts would be ideal.

Thanks guys,
Whopper

Go to the B5 A4 and TT subforum S and read the sticky posts. Everything you could ever hope to know is laid out there and the vast majority of it will translate to your B6 as well.