Shadow lines on faces on mesh I'm having difficulty of solving this problem. I'm making a high poly truck, though there are some shadow lines trying to fix up haven't figured it out just yet. This is my first vehicle model trying to make and in a sense, I think I kinda screw up the model a little bit as the UV unwrapping is kinda a mess, though I believe it isn't the way UV is set up because I have two different UV maps, it still shows the shadow outlines in solid mode, and I've moved the lighting around. If anyone knows the answer to this, or have a similar situation would be greatly appreciated. 

Thanks
As LukeD commented, meshes should consist of quads of roughly the same size. A standard way of rendering faces is to take a color assigned to a given vertex of the face and linearly interpolate the color across the face to the next vertex. So if your faces are not roughly uniform in size, you can get these long shadows stretching across the surface of your model.

Basically, the lights in your blender editor illuminate the vertices. If one vertex of a face is very far from another vertex, the vert farther from the light will be assigned a darker color, and the "color gradient" across the long face is very noticeable (because it's just evenly blending the colors of the vertices across the face). If you add more polys, there will be more vertices to illuminate, which will give more accurate coloring.