Trying to be a bit more helpful here...
What are you trying to capture? Think about what is interesting about your subject and try to get that and make it really show in the shot. Ls3D is basically trying to do this by taking the more distracting elements out.
Consider what's in your shot... is it valuable to the shot or not? What are the cars doing? Why are they there? How do they contribute to (or take away from) what you are trying to accomplish?
etc.