Looks awesome! If I may make a small suggestion - do you see the glass poking through the billboarded glow on the passenger headlight? I figured out a way to fix that kind of behavior when I was playing around with glow effects a while back. For the billboard itself, make it the same diameter as the longest diagonal length of whatever object is supposed to be glowing (the headlight in this case - the diameter you are using looks about right in this screenshot). Then, offset the two polys of the billboard to half that distance in the -z direction in object-space. Finally, place the center of the billboard at the center-of-mass of the headlight. That way, no matter what angle you look at the headlight from, the glass will never be sticking through the billboarded glow effect.
--EDIT--
I drew a diagram in case my description above doesn't make any sense:
If you wanted to be really creative, you could put three smaller less transparent glows per headlight inside/behind the large glow (one at the COM for each bulb) using the same method I described above. That might be a little bit of overkill...