What I remember about the "Yard Sale Lady" was that the van was said to be driving "like a bat ...." and that (going strictly on memory) the driver seemed to bear the likeness of someone who has often been associated with certain illicit activities. (But that is going strictly on memory). I'd rather not put a name to this individual.
I have no idea if this woman was thoroughly questioned or if it was knocked down but in reading her comments on another forum or somewhere that is my recollection.
I don't know of anything that would rule out the Yard Sale Lady's story but I believe the witness statements of the N-L paper carrier implicitly. After all she drove the same route delivering newspapers every morning she worked and would certainly notice things that were out of the ordinary. She came forward immediately and reported the van she witnessed parked on S. Kentwood at 4:30ish AM, among other things. Does that leave enough time for the YSL's sighting also at 4:30ish? Certainly. But I have a hard time with any witness who comes forward years later making the claim they called SPD but no one bothered to call them back; I just don't believe that! Every tip taken by callers was written down on an index card and investigators were sent to interview the witness and turn in what they found out on that same card. That's how the FBI does it and Knowles caught a lot of flack for "micromanaging" the investigation. And if the YSL really saw something she felt was important wouldn't the onus be on her to keep trying until she got someone to listen, or does she just forget about it until years later? I would also question her being out at 4:30 AM on a Sunday morning putting up signs for her garage sale. Each will form their own but it just doesn't add up in my opinion.