The brake light thing. From what I remember is some sort of transparency issue. The issue is our scene traversal is different from the hardware itself. My best guess is the hardware is doing some sort of basic scene sorting, but I've not been able to figure out what. Tried maybe 10 different things which have whilst worked, have no replicated what the hardware itself is doing.
I think it also does a depth pass on some transparent surfaces (like shadows) that totally eliminates z fighting.
I'll check out the fog thing