First you must open your application Macromedia Flash 8 and run application. Okay, Now we lets begin for trace. For this trace I use car for object. for import your image File>Import>Import to stage (ctrl + R)
Now grab your selection tool and make a nice little curve in the front of your car, I do it that way the corners of your car is straight in front of your window corners, and then I add the curve... After you have done that... grab your line tool and make some lines which makes the car look more realistic, here is my final result