I like to put in my two cents as well. If you want to paint the front clip as a whole, pre-paint the edges of the panels before assembly to get paint in all the nooks and crannys that cannot be otherwise reached when assembled. If you paint everthing separate, apply masking tape to all the edges that come close to anything hard. During assembly, if a part rubs against something else, the masking tape helps avoid chipping your fresh paint. During your mockup, it is critical that you make the parts go together easily. If need be, elongate bolt holes so panels line up correctly without stress on the parts. If everything falls together the reassembly will have much less chance of paint damage. By the way, only solid colors should be painted on parts separately and at different times, metallics should be painted all at one time.
Joe