^ I agree with you...but OP asked for inexpensive mods.
OP, no offense but are you in high school? If so, take some advice from someone not that old (I'm 27) and don't mod your car unless you are going to get some performance out of it. I modded the hell out of my Accord in high school and I now feel like a total dumbass because of it and I assure you I'm not the only one with that feeling.
Like Kubica said, start with some good tires and light wheels. That will basically add some free performance. Then when it's time to replace suspension (don't throw away a working suspension...), go with upgraded parts.
No one is saying don't mod, just do the important stuff first so you don't end up with no money and a broken car.