This is very nice and i think its very cool. but I was wondernig if you could help me understand something.  I am trying to learn 3D modeling and been watching lots of videos trying to decide which softwares to learn. I try blender but want to learn more. Then I see you using all of these softwares and not sure why it is you need them all. 
No offense but those look like daz studio characters and things I can inport into daz. Are you saying you modeled the cars and stuff in zbrush and set up the scene in maya? Or did you make the girls, or the ground and trees, or created the clothing? I just ask becuase this looks like something i can do right in daz without all of the other softwares. 
Sorry for the long comment byt i am just confused and trying to learn what softwares are used to do what things. Thankyou!

Hi there. I just commented on one of your other pictures, and I am curious also. I like the ground, water, and trees, and would love to know how to do this. It looks really cool. 

Thanks for the comments. The models are all done with genesis base mesh in Daz, imported into zbrush where I used pictures of my wife, daughter and family friends to create the completed models. each of the cars are free 3d models except for the Mitsubishi Eclipse[e which I modeled in Maya (This is a true replica of my wife's car with the hood wrap). The characters was all posed in zbrush as well as the ground creation. The forefront trees are 3D objects as well., then everything was imported into Maxwell Studio and assembled. I rendered the scene in Maxwell Render and the rendered image brought into Nuke, this is where I added the 2D background of the other trees, water, sky etc...
You can use whatever software you choose to create your vision, I use many software because I create different things with each, I use Maya along with Daz genesis base to create my desired base model along with zbrush for more detail. I use Nuke as my compositing software to combine my models and 2D objects to complete my scenes.