Wow,
for the kind comments everyone!!
You keep me motivated (much to my family's disgust ;-)
Greg, H, The foreground was taken 6:03pm (about 10 minutes after sunset) but I did take them quite dark (1/10, f5, Iso 200)
I did try it with a slightly darker foreground, but it wasn't as good, so I ended up using it straight out of the camera with some additional saturation. I tried to match it to "reasonable moonlight".
The main starshots were taken at 9:09pm. Yes I did "up" the saturation on the upper component (+30 in camera raw). It probably is a little excessive.
To maintain the line-up, I marked out the tripod position on the road, kept the tripod extended, packed it up in the car, and came back 3 hours later.
I am definitely going to work more on the foreground background blending. I don't like it from a photographic point of view, but you do get much better results.