I've also had good luck with Meguiars products, specifically Ultimate Polish and Ultimate Compound. If you don't feel the scratch, it more than likely can be removed. If you feel the scratch with your fingertip, you will not be able to remove it.
If you want even longer protection from the elements, use a paint sealant. With Rejex or Collinite 845, I typically get at least 6 months protection.
For more info about taking care of your car paint, visit the autogeek website.