Well I think Carty and red_s13 are on the right track
In my opinion I believe this effect is accomplished by using multiple layers, filter effects and contrast adjustments.
Heres what you do.
Pick a suitable High Res shot of similar layout. Another words, good lighting, depth of field and not alot of distracting elements.
Select, cut and paste the car to its own layer above the original pic.
Back on the original, grab the retangle selection tool and starting at the top select the whole width of the pic and pull down. On this particular example he went all the way to the bottom front edge of the front tire, but it really depends on the pic.
Copy and paste this to a new layer above the original.
Now, on the layer you just made, Filer > Blur > Gaussian Blur and you get the out of focus, depth of field background. Dont get too crazy with the amount of blur, but you want enough for it to be easily noticable that its out of focus.
Now go to the new layer you made of the car, which should be your upper most layer now, and duplicate it. On the new layer go to Filter > Artistic > Poster Edges. Adjust the levels there to suit but to get something like reds example here your going to want to make it subtle. On the example I have posted I used an Edge Thickness setting of 2, Intensity of 1 and set the Posterization at 6.
After you make your effect on this layer you then will need to use the eraser tool and get rid of a lot of extraneous dark areas on the car, leaving the outline around the car and anywhere else thats looks good to you. You can then go to the layer right below, grab the blur tool and smooth some of the hard edges out for further smoothing effect.
Add a few highlites on another layer on top of everything.
Then merge your layers, save it as a JPEG, then back off the merge to keep your original .psd intact and save it too.
Then I opened the JPEG, selected the car once more and made some brightness/contrast adjustments to make the car more vivid.
This took me a little over an hour to do the car and write the post.
Probably would have been better to use something besides a black car but I just grabbed the first decent pic I ran acrossed.
Hope this helps.
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