You better put a dark layer behind the render. Look at the edge`s of the car. Looks like its pixel bleeding but its the way it transfers from pnf to jpeg. Just put a dark layer under it and it is gone.
Hm^^ Not a bad idea. Maybe I'll start something like that. At the moment i have to finish a Bar 2004 request for the F08-Class. After that i will think about your idea...