The last floater is the pine branch in the fore ground.  I created a shadow, distorted it, and placed it in front of all other layers/floaters so the shadow falls across the mailbox and fore grass.  I adjusted the opacity until satisfied with the results.

I dropped all layers/floater. I added some grass around the side and front of the truck. I also added some shadows to the trees in front of the red house. I cleaned up the sides of the road and edges of the grass.  

Below is an example of the finished painting at 50%.  Below it is a portion of the painting showing what it might look like on a moonlit evening.  I hope you like the finished painting.