Another spray-painter who can also take up the challenge and which I can recommend is ADSM (Advance Scratch Master) located at no 33 kim chuan drive (tel 6858 3255) or at no 53, paya ubi industrial park (tel 6747 0738). Look for Yong (hp 91006666), say that the Mixmaster recommended you.
ADSM changed the colour of my merc from tealite blue to black. Here you can see a pic of my merc being worked on
Quality of work is quite good and their workshops, especially the one at paya ubi, are really clean.
Can check out ADSM's website at
http://www.adsm.com.sg