Nice shots dude, you're racing down a distinguished road there man! My gallery was founded on the principles of darkness and night, so a big 👍 to you! I like how you are trying to re-create night shots too, and its nice to see the improvements each time. I started out like you, with experiments, and I still experiment now. The secret is to make little improvements each time, eventually it will fall into place. 👍
Here are a couple of tips: If you want to create a great night shot, study each track and the direction, strength, and type of light there. It's not just a case of darkening the picture in PS, you have to create the look and feel in game first - Thats how I create my night shots.
For night shots, depending on the time of night I'm trying to create, I use heavy negative EV values. By heavy, I mean in excess of -5 for really dark images I go to -10. Also, if your nearer even EV values (-5 to 0) think about a slight shift towards orange - IMO this gives an early/late evening feel to the iamge. If your nearer -10, use a slight shift towards blue - IMO this gives a feel like the dead of night when the moon is shining down. Also think about using the mature setting too. Vivid is great in the day, but colours don't stand out so much at night. I hope that has helped a little. If you need any further ideas, feel free to look through my gallery at my darker updates, you might get some ideas. 👍
Keep those night-time experiments coming man! 👍