I got the same car as yah. I haven't had the $$ to do anything to it yet, other then dropping in a cd player and changing headlight bulbs.
-The headlights are a lot whiter and more powerful and are great. They are sylvannia cool blues. But if you like the bluish look of the new lexus and bmws, then try the xenon bulbs.
-As soon as i round up $100+, im going to drop in a kkm air system. It'll give yah great sound and the tiniest increase in power.
-the cd player and the audio is a personal choice, the dude above me has his opinions. But i say go ahead, put something in that you can enjoy (speakers, subs, whatever floats your boat). Just don't make it obnoxious.
This is your car, have fun with it!