Oh yea, or a new headunit if needed for tunes ... about 140$
New speakers, if needed ... about 80-200$

If you have good head unit/speakers, try for an amp/sub ... easily the whole 200$

If you're dying to spend the money on your car, you can do a decent bit with 200$ as long as you shop around and play smart. Just figure out what you want most and buy it. Then, when another 200$ comes along, do the same thing.