I did some chops already!!!
Here's a repost of what I did:
The aura around the edges of the car...I saw them, too - when I was chopping. I attributed them to that dull-cloudy-day light deflecting off of the white paint.
If you separate the body onto it's own layer, try using the saturation element to completely grayscale both the new body layer, and the edges of the background layer.(lasso tool)
That seemed to work for me, as most everything PS has to touch is black and white.
And black34v6, Ramero15; Pretty darn Nice chopping!!!!
