Following Seas - Ghouls and Godrays 

I've managed to (imo) improve the lighting. Was a bit of a pain to get this working on moving vehicles, but is essentially a couple of zoned reflection probes coupled with geometry that ignores exterior probes. Not perfect, and some flicker occurs, but it's a good start.
I've added some dust and particle based Godrays as well. These are tied to the environment, and will shift color (and eventually intensity) based on time of day.