Car may be minus oil note (9)
I believe the answer is:
limousine
'car' is the definition.
(limousine is a kind of car)
'may be minus oil note' is the wordplay.
'may be' indicates an anagram.
'note' becomes 'e' (musical note).
'minus'+'oil'='minusoil'
'minusoil' anagrammed gives 'limousin'.
'limousin'+'e'='LIMOUSINE'
(Other definitions for limousine that I've seen before include "Luxury car" , "Luxurious car (with a chauffeur?)" , "big car" , "vehicle" , "Large luxurious car" .)