I’m not an expert with the clone tool but I wonder if that realy is the best way to resolve this situation.
I’ve used it only to remove specks, and you have to keep in mind that the spot you sample from updates with the video.. unless that can be changed.
Anyway, I would track the footgage if needed, paint out van in photoshop, place that over in AfterFX and roto the person walking in front of the van.
http://www.ardillamedia.com