Map attached of area just south of Webster City town center. Doc's truck stop marked with T. Boone River and Briggs Woods Park (with reservoir) just south down Rt 17.
It seems that Jay would park near the river or Briggs Woods Park, if his intent was to go there. Stopping at a truck stop north of that area does not seem logical.
It strikes me that his car was found at a truck stop on Route 20, a major cross-Iowa highway. Seems the only reason for Jay to disappear there, would be getting picked from someone traveling Route 20.
Or someone put his car there to make it appear he was picked up by someone traveling Route 20.
Words matter. The articles so far imply Jay was identified as being in his car at the truck stop, but not sure if that is poor journalism. Maybe he never was there.
Rambling and confused...