I recently bought a 2004 XK-8 with Quartz paint color. I ordered some touch up paint, and it is simply too dark. However, the paint does look like an excellent match for a "Slate" colored car; darker than the Quartz color! If anyone happens to be in the Phoenix/Tempe area, or passing through, I would be more than happy to make it available to you if you can use it! I have a small touch up bottle of it, and a detail "pen" of it. I realize this may not be a PERFECT match for you, but we can try it and see! Contact me through the site, or 602-448-1868 Kevin