Unwelcome revelation seen on back of car (7)
I believe the answer is:
spoiler
This could be a double definition.
'unwelcome revelation' is the first definition.
Although both the answer and definition are singular nouns, I don't understand how they can define each other.
'back of car' is the second definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Maybe there's an association between them I don't understand?
'seen on' is the link.
Can you help me to learn more?
(Other definitions for spoiler that I've seen before include "Aircraft wing flap" , "giveaway" , "Disruptive competitor" , "Aerodynamic surface on car" , "Destructive person" .)