I tried the internal glowing parts trick myslelf, it rarely works. That's why I model actual ridges into the warp grilles now, and then assign slightly different textures to both. It means I can make the raised areas less transparent so I still get the line effect but it looks good close up. Usually I give the ridges a brassy or gold tinge as well, to make them look more metallic.
I took your advice, but ended up going in a slightly different direction. I've got the clear cover, then 20 or so thin coppery pipes/tubes just over that to simulate the ridges of the original model, then inside the warp nacelle I've modelled some very basic warp coils to break up the horizontal blandness. Then I've stuck a bunch of lights inbetween the gaps. The rest is just cheap and nasty post effects in Photoshop right now (the final would use HDR in After Effects)


I'm not sure about the technical accuracy of this. I wasn't sure if it was the coils themselves that were supposed to glow, but in my renders the coils are the darker parts, and the lights inbetween are creating the light. If that's not correct, I could alternatively try giving some self illumination to the coils, and ditch the lights.