Out of curiosity, how many coats of clear did you spray on your car? It should be at minimum three coats of clear. Then you should only sand your clear coat lightly with 1500 grit and move to 2000 grit sand paper to finish. Remember that both of these steps should only be wet sanding the clear. Then like Grant said, you need to go to a automotive paint supply store, not autozone or pepboys, and buy a bottle of meguiar's medium grade buffing compound and a bottle of meguiar's scratch remover.
Also, if you do end up re-painting the part with color because you wanted to start over. Do not sand your color paint before you apply clear. I repeat do not sand your color before you apply your clear coat. This will lighten your paint color up significantly.