Just discovered, God's ray does not work through a headlight glass. That is something I'd like to work on. Having very realistic headlights. Not only on vehicles, but aircraft and spaceships as well. I should do a drawing of what I'd like to have happen, shouldn't I?
"Come with me if you want to live."
I just checked and it does work. What I think happened here is that your glass in a glass on the one side but not the other, so you can look inside but if you're inside, you can't look outside. That's why I always suggest to group an object like the glass and apply the material to the group not the face so that all of the faces of the object have the same material.
It's working for me just the way you have it and if I max out the ray settings, it's very much working. Remember, the God's ray ONLY comes from the source and not from reflection as this would be too much time for the render to process. Your light bulb is also illuminating the back, outside of its container.
You know what I'm going to do? I'm going to turn the Performance mode option red and bold when it's on because I do make that mistake as well and it's annoying. If it's red and bold, we'll see it right away and turn it off, no more thinking "WTH am I doing wrong???".