In photoshop I used the pen tool to outline the shape of the exterior of the Hudson and to cut it out and place it on it's own layer. I also took out the side windows as the brick house in back showed through. I made a new interior piece using some of the colors I took from the remaining front windshield and put it on it's own layer. Since I wasn't going to see the lower part of the car I didn't cut it out as closely but it would not be a bad idea to cut the whole car out and then cut the wheels off so that they could be animated to be turning, if needed.
I also used another still picture of the same car for the interior, seen behind our actor. I cut out all the windows.
Back in After Effects, I worked on the background plate and animated my cut out still of the Hudson to cover the modern car as it passed. This was as simple as setting a position keyframe of my Hudson hood over the modern hood and another keyframe on the Hudson Trunk over the modern trunk as it passed by. I tweaked the movement a little bit dragging the Hudson still back and forth till it worked and then setting the motion blur for the still which really matched the modern car very well.
