I think 100% if the police rule out those four vehicles they are wrong. I can't see any scenario that would lead to him being in the area for 24 hours (although it could happen I feel unlikely)
Just because police cannot prove he wasn't in one of four vehicles doesn't mean that he wasn't in one of them. Lack of DNA evidence means absolutely nothing at all. But if they cannot find a trace of him anywhere then eventually their search area will become so big they cannot find him.
It's well on its way to a cold case unless there is serious info being held back.
Edited to add its opinion there's no dna evidence from the vehicles and horseshoe searches as we don't yet know.
Just because police cannot prove he wasn't in one of four vehicles doesn't mean that he wasn't in one of them. Lack of DNA evidence means absolutely nothing at all. But if they cannot find a trace of him anywhere then eventually their search area will become so big they cannot find him.
It's well on its way to a cold case unless there is serious info being held back.
Edited to add its opinion there's no dna evidence from the vehicles and horseshoe searches as we don't yet know.