here i had a very muddy field bad bad background but i liked the cars ... so
i actually painted the background black around the original car, then opened a new black canvas in black double the size of the original photo, Then dragged the whole of the car image across.. then dragged the same image across again so i had two of the same car on the one canvas... then went to "edit" "transform" then "flip canvas vertical" so now you have a car the right way up and one upside down. goto the layers pallette and click on the upside down car layer... and change the opacity to 29%
when your happy with the positioning of your images then goto "layer" "merge"
all done
i also used a blend mode of soft focus on the cars .
the finished product pictured below