I think the best odds are that she will be found closer to the mall area than JM's house. I think I recall that he lived a short distance away, like 12-15 miles? I currently live about 14 miles from my most previous home, and my husband works in that city as well. I have to go there to drop him off and pick him up. I enjoyed living there and it is much nicer than where I currently live. Due to all these factors, I spend basically all my free time there. I'm more familiar with that area than I am with my current area, even after a couple of years of living here. I think a lot of people are like that.
So IMO, the car was used just to get her to a secluded enough place to do whatever it was he wanted to do. I would also be checking the river. He may have just drive her a few miles upstream. I'm sure there are plenty of dark, deserted places along the river where one could easily shove a body into the water. Come to think of it, if she was drunk, it may have been all too easy for JM to drown her, a cause of death he may believe an autopsy could deem "accidental". JMO
