Flyer parking free in great convertible (9)
I believe the answer is:
partridge
'flyer' is the definition.
(I know this)
'parking free in great convertible' is the wordplay.
'parking' becomes 'p' (abbreviation on road signs).
'free' becomes 'rid' (to be free of something is to be rid of it).
'in' indicates putting letters inside.
'convertible' is an anagram indicator.
'great' anagrammed gives 'artge'.
'rid' inserted into 'artge' is 'artridge'.
'p'+'artridge'='PARTRIDGE'
(Other definitions for partridge that I've seen before include "1st" , "Game bird (in a pear tree?)" , "Widespread bird" , "sort of quail" , "Peculiarly apt girder for the game bird" .)