Is he as good as gold? (5)

I believe the answer is:
oscar
'good as gold?' is the definition.
Although both the answer and definition are singular nouns, I cannot understand how they can define each other.
'is he' is the wordplay.
I cannot quite see how this works, but
'he' could be 'car' and 'car' is present in the answer.
The remaining letters 'os' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
'as' acts as a link.
Can you help me to learn more?
(Other definitions for oscar that I've seen before include "trophy" , "Hollywood statuette given as annual award" , "-- Wilde, author" , "Comms code for "O"" , "Film statuette" .)
