maybe I’m wrong but the one thing that makes it look unreal to me is the total lack of reflections on the vehicle.
Cujo 31
I think you can make the reflections in a simple way. These will not
be very realistic, but would add to the image.
Sorry if i am trying to give a too much of an advice here.
Put the orange firetruck shader to reflect a small amount, maybe
one quarter amount. Then set a plane with your background image
as col map to following point. Imagine a ray leaving the camera, bouncing from the vehicle and then going forward about 30 yards and stopping there, that is a place for the plane that makes the reflections. Emit on the plane to 100% in other terms ambient to the plane 100%.
The plane should be far enough so that it will not show in the image.
Reflection amount on the orange shader should be so small that it is a subtle reflection.
Did you do postprosessing on the latest one?
Ok…
I used a Geo-Dome to get a reflection…not perfect… but well it’s a start…
Are we getting closer?
Thanks!
Cujo
Its getting better.
I think you should be able to see the background landscape through the windows of the truck… if its too complicated, just try to give the right side window a green blurred color and it should help.
The colors of the truck really don’t match the environment. They are too much saturated. The answer to that problem is in either the lighting or the material colors.
Look carefully under the front wheel on the right side of the truck. There is a 1 pixel wide white line.
Sorry for the poor English. 
Reflections+
Aluminum+
Two things and i would call it done. The sign to the right back and
get the white pixels around tires away.
The white pixels away in post process if there does not seem to be another way.
If the white pixels are only one pixel here and there undepended of resolution, then you could render it triple times pixels of the final image and reduce the image size or do maximum osa. I am not sure, but this might work.
Aww man why’d you delete the sign? It was looking good enough that few would realize it wasn’t part of the original image. 
Ok gang…
I am considering this project done… I need to move on…
But I would still appreciate any comments etc…
Thanks for the help!
Cujo
Great! It improved quite a lot! I was a good idea to move the firetruck so it appears bigger.
Up two images in this thread was probably your best to date sign implementation. The newly added one just looks pasted in. Coming along though, still needs some work though. Keep at it though you’ll get it!