need some photoshop help

been working on a car but i don't know how to get the panel joins/lines done, you know where it looks like the panels touch each other...sorry don't know how to word it other than that..i think its the original colour then embossed or the like ..any tips you photoshop users ?
its probably very easy and i've done it before but my mind keeps on farting at the moment and i can't think for s.h.i.t