We recently purchase a 330i 2003- sport/premium. The car had 43,500 miles on it but looked pretty good. After I washed it, in my thorough fashion, and waxed the oriental blue metallic paint, the car looked wonderful. The only exception is the number of paint small chips due to rock impacts. None of the chips went to the metal but a white undercoat made the chips very noticeable. I've lurked it the NG for awhile and this is my first post. Some time past, I read someone saying, "ditch the matchsticks and applicator brushes in the touch up paint bottle." Their recommendation is to buy an appropriate, small tip, quality paint brush. Yesterday, I went to a hobby store and bought a decent brush. It feels good in your hands and has a tiny pointed brush. I accomplished the touch up. The car looks great.
It's a numb skull post, I know. But I've owned a few cars in my time. And I have been forced to touch up the paint chips. It's just amazing, to me, how long I've struggled with all the different applicators but never being satisfied with the result. I spent $3.00 on a brush that I can re-use, and I'm happy.
Thank you for saying what should be obvious but sometimes it is not! Some people need help to get a clue :-)