One on patrol reported pimp about to run (5,3)
I believe the answer is:
panda car
'one on patrol' is the definition.
(informal term for a police car)
'reported pimp about to run' is the wordplay.
'reported' shows a homophone (sound like).
'pimp' becomes 'pander' (old-fashioned term for a pimp).
'about to' becomes 'ca' (I've seen this in other clues).
'run' becomes 'r' (cricket abbreviation).
'pander' is a homophone of 'panda'.
'panda'+'ca'+'r'='PANDA CAR'
(Other definitions for panda car that I've seen before include "station wagon?" , "One patrolling" , "Police vehicle" , "In official vehicle" , "Something with copper inside?" .)