What a sad case and sad silence.
I am hopeful her remains will be found eventually - in such a densely inhabited area, hard not to. This is not a large bog or an untravelled stretch of the mountains. An up to ~30 km drive on a rural landscape has opportunities, but they are limited.
There must have been a reason to drive to the Spalding/Cowbit area. It's been suggested it was more about framing her friend and placing her phone in the area than about the actual disposal of remains, though the latter still remains a possibility.
The critical time period seems to be the ~1.5 h around noon:
Unfortunately by now I am unsure, if we should look east, north, west or even south. I was a bit intrigued by the landscapes
near PMK recycling, and River Welland crossings, but I am not sure how likely water disposal is. On the one hand he does not strike me like a guy that will have the patience for digging, on the other he did frequent the garage for some reason (tools?) and also the fast food place (why? alibi making?).
I do hope she will be found eventually.