Straighten out those UVs. You'll have a hell of a time painting sharp details at a diagonal at that texture size. With smaller textures, you really want the UV edges to be as close to vertical/horizontal as possible without introducing too much stretching/warping. The main shell, for example; you can straighten out the back row of edges. The side panels should probably be overlaid on each other (go with the orientation of the top one). Looking at the flats, you're going to want to move and resize stuff to maintain similar texel density; right now the main shell is being given less than a quarter of the texture space, even though it's going to come under the greatest scrutiny. You can probably get rid of the underside entirely in the geometry, unless you plan on being able to see it, in which case you can still reduce the size of it in the unwrap significantly.
Also, what jakten said about the wires sans transparency. Show us wires from various angles.