Congratulations on owning one of the most capable Stock Race Cars AVAILABLE.
Do NOTHING to it now.
Learn how to drive and drive it! Learn Everything about the car, learn it's sounds.
Appreciate the car, Then;
Take it to a local Autocross! And REALLY Learn. Or you could hit a Performance driving school.
Read my advice about what to do Before you start modding.
It's a great hobby but, look before you leap.
GoTo my buddy Daves Site to see some cars in action "even me" and learn how to get involved in racing and AutoCross, It is an exhilarating experience.
http://www.autocrossnyc.com/
Good luck,
A.