Piece of Megane exhaust found in Clio, perhaps (4)
I believe the answer is:
muse
'clio perhaps' is the definition.
(Clio is the muse of history in Greek mythology)
'piece of megane exhaust' is the wordplay.
'piece of' suggests taking the first letters.
'exhaust' becomes 'use' (I've seen this in another clue).
The first letter of 'megane' is 'm'.
'm'+'use'='MUSE'
'found in' is the link.
(Other definitions for muse that I've seen before include "Think - goddess of the liberal arts" , "Cogitate" , "Goddess; rock group" , "Be absorbed in thought" , "Inspiring goddess" .)