Yes, seems like money has been his motivation, he also takes his victims from the scene of the crime. With his demonstrated poor impulse control, I think if the situation escalates he becomes violent. I mean think about it, what could his motive have been for taking Aniah? Sexual, maybe? But could have been more about money, was he going to force her to withdraw cash and it got out of hand too quick? It wasn't for her car, he was smart enough to get rid of it quickly.
The Dr. Phil interview with Walt & Angela, my mind immediately went to the person who was posting so much on social media. Is she the one they are referring too? Honestly, I feel like that is grasping at straws. In the end, they will find this was simply being in the wrong place at the right time