Use the marching ants to highlight the windows you want tinted, use the poly lasso tool, it the easiest. Then go to image-adjust-brightness/contrast. You obviously want to make it darker. If you want it to look pro take a little contrast out of it, so you see less of the interior. I also did your far side windows too. Oh and your front because there is less light entering the car therefore making the interior a bit darker. Oh and for the windows that you see from the inside, dont make them as dark as the the other ones because tint you can see out of better then looking. Try it and Post.