The first thing I did to yo my cavalier when I got it. Well first off it had jsut an am/fm radio....i didn't go out and buy a cd player. Actually the first thing I did was put on a louder muffler, then tinted the windows, then got aftermarket cd player. Which is a really super nice one. Then came my clear corner lenses, short ram intake same time as the euro tails, then my stereo system, now my rims.
Since your car has high miles, you might get rid of it instead of keeping it. So think hard about your decision before you start upgrading it because you never know.....one day you could come outside and your car just died. And you will have to think if you want to fix it, or just get a newer faster car than what you have.