They found hair in the trunk of a car rented 25 days after the disappearance. Find your suitcases, travel gear. What are the chances that a wheel catches some hair that was pulled off a brush and fell to the floor after her mother brushed her hair? Just a thought.
You might find strands of hair but not CLUMPS of hair. Clumps of hair fall off the scalp of a disintegrating corpse.
It was BODILY FLUIDS in the trunk of the car that the cadaver dogs hit on. Decomposing bodies give off two chemicals that live bodies do not, called cadaverine and spermine. This is the evidence the Portuguese have, and on which they will base their probable cause to arrest the McCanns.
The chances are slim.