Yes you can, but don't put so much expectation to it because it won't
shine like the normal car paint. If you just want to fill the lines, then
it's ok lar.
Last time my car was scracthed by some stupidos. I used
the crayon to fill the cracked parts because it's quite deep enough where
the metal parts of the door can be seen. Paint work completely
gone already. So it's a temporary solution.. to avoid rust.
http://img.photobucket.com/albums/v127/Dremel/apecelake1.jpg