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.
Sounds like she had to have been alive for part of that time. I couldn’t imagine what a mess a corpse would be after 25 days.