Removing minor scratch

If you are comfortable polishing the car, or at least the spot, Griots has some of the best poliches and clay bars I have ever used. http:\\www.griotsgarage.com
Just call them up and their staff can answer just about any question.
If that fails, their is also wet sanding, but I would start with clay and polish.

 

3M's Perfect III scratch remover is awesome. You can get it at a good auto body supply store.

 

Well, since you cannot feel the scratch, you have a chance of getting it out or breaking down the surrounding paint enough to make it invisible to the human eye. Wash the car and then start working the area with the least aggressive polish you can find/have. Continually work your way to more agressive polishes if the scratch is not coming out. After breaking down the surrounding paint to hide the scratch, wax or put a sealant over the entire area to protect it. If you do need touch up paint, check out www.autovisuals.com . They offer some great paint pens that are much easier to use then your typical brush for touch up jobs. Hope this helps.