get the 3-step system from 3M. 1. Fine Rubbing Compound 2. Swirl Mark Remover for dark colored cars 3. Imperial Hand Glaze Then just slap on a coat of your favorite wax (which had better be Mother's Pure Carnuba Wax) and your car will glow with a near-flawless surface.
There will be an initial investment of like $30 for all this, but it will last all year long.
P.S. Go easy with the rubbing compound (it removes a little clear coat) and use long straight motions with it ... everything else is a circular motion though.