If it's a small rock chip, I highly recommend getting some Dr.Colorchip touchup kit. I was really skeptical, especially since I have Sparkling Graphite, which to me would seem like a really ahrd color to match. I was extremely with the results, can't even see the chips anymore and it took no time at all. Now if it's a big chip, the kit still helps, but you'll still be able to see it.
I've decided that this car is a keeper. She'll get a full repaint in a couple of decades if need be, but I enjoy driving the car way more than spending half my weekend detailing it.
2008 E92 M3: Sparkling Graphite | Bamboo Beige | 6MT | CF Roof | HRE | Eisenmann | BPM Sport | Swift | Arkym | Mode Carbon | M.Perf