the problem with working on concept art work is secrecy. It's very frustrating working on something that no one will ever see until a few years (legal concerns). So here's one that I drew over some stuff I did... still very far from the stuff my client asks from me but I get to use the BG elements I made....
recycling is cool.
hope you dig...
this is just an exercise in rendering, not really in design... it's simply a terran version of Halo's Scarabs

edit: changed file. different coloring method.
Oh and yes concept art is frustrating it is like asking for icecream but you never get it until you do really good T_T