PAINT

It has taken me months of experimentation to come up with some good solutions to dark cars. First, if you have a garage, do your cleaning/polishing/waxing in there under florescent lights, as for some reason, this type of light shows all the detail. I have a dark cranberry PPG Group 4, so I am sure I deal with your same situation. For washing, I only use a very damp terry cloth towel, lightly just taking off dust, etc., then dry that section right away, letting the dry cotton towel do the work. I do this regular when dusty/dirty. Sometimes I even use distilled water (but that may be going too far, occurring when I miss my Prozac).

For polishing/waxing, you don't want anything that is going to scratch the surface, creating more problems (some products have minor abrasives). Even some of the so called fine cut cleaners/polishers put scratches in mine. Just do the florscent light test mentioned above, and you will see if the product is helping or hurting. I have found Meguiars Glaze #7 to be the best for "polishing", and then a good paste carnuba wax to seal it and finish it off. I got some Meguiars Scratch-X also, and tried some of this on the small scratch areas that the #7 didn't get out. I do it all by hand, not using orbital buffers (but I suppose low speed may be ok).

Check out the Meguiars website, as it has some other tips too. But if your paint is in very good condition, I would suggest the above methods...at least it worked for me.

RC
I had a friend who had the most perfect black paint job I have ever seen. He used a combination paste wax and corn starch as a polish/wax combination. He would do only a 1 square foot section and rub the product in very lightly in a circular motion. He would use a flannel type rag (like pajama material) for the polishing and a well washed cotton towel to remove the residue. Results on his particular paint were outstanding.
Lar

Could be your California Duster has some contaminate in it that is scratching the paint. Also, what type of light do you see the scratches in? My painter pointed out that stuff that looks real bad under flourescent light doesn't even show up in sunlight. Finally, I have had a lot of sucess with the orbital polishing system from Griot's. Check it out at http://www.griotsgarage.com/index.jsp
The system I bought is the Porter Cable with the 3 different grades of polish and their "best of show" wax.
Good Luck
Gary