Hated former editor keeping old car (9)
I believe the answer is:
execrated
'hated' is the definition.
(execrating is a kind of hating)
'former editor keeping old car' is the wordplay.
'former' becomes 'ex'.
'editor' becomes 'ed'.
'keeping' indicates putting letters inside.
'old car' becomes 'crate' (informal term for an old car).
'ed' placed around 'crate' is 'ecrated'.
'ex'+'ecrated'='EXECRATED'
(Other definitions for execrated that I've seen before include "Cursed; detested" , "Condemned" .)