I know this sounds like an silly solution, but I'm really suprised nobody else seems to do it.

I use crayon. Think about it, what is a crayon other than a colored wax?

On my green car, I'd use a green crayon. On my black xfire, I've gotten some scratches too. I rub a black crayon into the scratch or area to kind of fill it and get rid of the white color, then use a little compound polish over it. Haze and wipe off. Then take a wax (not a polish) and go over it again.

If you don't have polish, just the crayon and wax will look good enough and won't be noticable. For those of you who don't know, polishes and waxes are different. Polish is for shine and is usually a little abrasive. Non abrasive polish is best for newer paint like on the Crossfire, but something a little abrasive is good for a scratch or group of small scratches. Wax is for protection and keeping the shine.

The drawback to this you'll have to do it every 6 months or so on a scratch, as the wax from the crayon will slowly disappear, and the whiteness of the scratch will come back. But it's a lot cheaper than painting the scratch, and a lot better than just using wax or polish without the crayon.