Heres one of a crash I had (I was taken out of course ).
Edit - crash02 - tried to add some grassy type debris. Not sure if it's an imorivement or not.
it helps some; there should be different sized chunks though (i think... slightly different sizes though, not like huuuge changes) but to make it better i would do some layer work and give the car scrapes and make it look like some of the paint came off where its dented inward :up:
Used CS2, although im quite sure its in CS aswell, its called "lens blur" now that i check.. lets you add different amounts of blur at different levels of the photo.. great for creating depth..