That's my line of thinking. So hoping someone calls in a tip for the vehicle. Maybe the truck was scene on both days by different people.MO on a possibility:
Imagine LE tracks down the vehicle by cousin X calling in to say that sounds like cousin Y’s vehicle. Y is contacted by LE - “Oh yeah, I was in that area on the 14th.”
All while possibly LE has video evidence to point to the 15th during a certain time frame.
Again an opinion..
I remember the father saying in the first TV interview they had not located two persons of interest. The next day Leslie said they have interviewed everyone.
Maybe this tip came from the traffic stop they held.