Tracks made by pile-up with top fully down (5)
I believe the answer is:
hunts
'tracks' is the definition.
(hunting is a kind of tracking)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for hunts that I've seen before include "country pursuits" , "Pursues wild animals for sport" , "Chases and kills (prey)" , "Traditional county" .)