It is subtle. It disappears about 6" behind the door. It is also very hard to get a good picture of. It is a continuation of the bodyline on the lower door. It disappears before the rear wheel opening. This picture kind of highlights where it is.
Here is a picture that shows it about as best I can, really hard to take a picture of a mirror. You can see how it kind of tapers to nothing here about 6" behind the door, on the left you can see the shadow where the light is reflected differently by the line on the door and that feature gradually melts away to where by the right side of the picture the curve of the panel is smooth.
You have to be very deliberate in your sanding to keep the body lines from becoming rounded. The one trick is to tape on the bottom side and sand down to it, then tape on the top side and sand up to it. This way you do not directly sand the line or move it and it stays crisp.