Fire engine feature (5)
I believe the answer is:
siren
'fire engine feature' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for siren that I've seen before include "Warning signal generator" , "Bewitching singer" , "Dangerously alluring woman" , "Loud whistle or sea witch" , "Charmer" .)