PM seeing spy running behind car (7)
I believe the answer is:
autopsy
'pm' is the definition.
(PM can mean postmortem)
'spy running behind car' is the wordplay.
'running' is an anagram indicator.
'behind' means one lot of letters go next to another.
'car' becomes 'auto' (automobile).
'spy' is an anagram of 'psy'.
'psy' put after 'auto' is 'AUTOPSY'.
'seeing' acts as a link.
(Other definitions for autopsy that I've seen before include "Dissection of a body to determine the cause of death" , "An official post-mortem examination" , "Pays out (anag.)" , "Far from quick examination" , "final examination" .)