I'm still gonna try to verify the new info this weekend.
OM's W could be "seeing things" in the number of cars at the parents' house. or something else occurred.
e.g. He swapped vehicles with his mom to work on it before he goes back to school.
It's all circumstantial at this point.
The only thing I do know is she said she moved to XXX (community) and neither I nor OM's W have noticed either W or OM vehicles at B/MIL's Co-OP Project in the last two weeks. I last checked on Sunday coming back from shopping.
If I can be sure where either he or she is, then I know the sitch has changed.