What drove you to buy an automatic transmission car? I'm not ragging on you, I'm curious. h:

Don't bother with bolt-ons. Anything less than a built transmission and some form of forced induction is a waste of money. The 10 hp you get from I/H/E (intake, header, exhaust) will be a pittance compared to the inefficiency of a stock automatic transmission.

Honestly, I'd limit your build to suspension only.. or better yet, save your money and move on to a manual transmission car in the near future.

Sorry to be a downer, but unless you take drastic steps to increase torque and hp, there's little point in modding an AT-equipped inline-4.