I didn't have too many issues using it on my PW Z. I mean, I didn't go in there with high expectations due to the fact that PW is a 3 stage paint and knowing the only way i'm going to get perfect results is a repaint. But, it definitely covers the chips/scratches up well enough that it takes a good amount of inspecting to notice, but I can definitely see how if I had some larger chips or scratches in bunches that it would start to look like crap. But it is what it is, for the price you can't beat it.

anyone done it on 40th color?

I had to use it on my hood. It covered pretty good. You can see it if you really look or in the right light but it is better than before. I also used it to touch up a little rash I put on one of my rims. Not perfect but better than the shiny stuff under the paint that made me sick.

I decided to revive this thread since I've decided to touch up a few spots on the used Z I just bought. I was originally looking at the factory touch up paint with the separate clear coat, and then I found this thread where people mentioned Dr. Colorchip and Langka. Looks like I'm going to try out Dr. Colorchip.