Yes this. Plus her purse was in the car, there was no real attempt to hide the car or the fact that it belonged to Suzy, it wasn't dumped at a remote location. Whoever did this did it in a rush without really thinking much, except he probably wiped the steering wheel or wore gloves, or was someone who was known to have been in her car a lot so it didn't matter if he was linked to it. So if she did take particulars and things why not leave them there too? Unless she got out of the car holding them, but why would she do that if she didn't intend to use them to view Shorrolds Road?
There were people on that street during the day so if Suzy had been dragged out of her car or a body taken out (and why there?) it would have been seen. She was never there.
The main reason I think that BW is wrong, btw, apart from the contradictions, is that Suzy was a conscientious person who was very committed to her job. She could not have really spun a short lunchtime viewing into a 3 hour break to drive around with a friend. She would have gotten into trouble had she just gone off for the afternoon. If that was her abductor how did he keep her for so long in broad daylight? In the area where she worked and where someone she knew coudl see them outside? It makes no sense. And if you think about it BW was riding her bike and would have had only a couple of seconds to notice the passing car, which was a common make and colour.