Good point. Those UI’s have tons of useful tools.
Also it doesnt hurt to think outside the box sometimes. Even though it is not a static mesh, here’s how i had made the UV’s for my car:
It is easier to manipulate the vertices in the viewport. So you turn the mesh into a plane in the viewport, slap a planar UV modifier and then do minor adjustments in the UV editor. Then copy&paste that modifier to the original mesh. I got the idea from Zbrush’s UV mapper and it works. I could even make lightmap UV’s for it this way if i wanted to. 