Good English car sign (6)
I believe the answer is:
gemini
'sign' is the definition.
(Gemini is an example)
'good english car' is the wordplay.
'good' becomes 'g' (abbreviation).
'english' becomes 'e' (abbreviation).
'car' becomes 'mini' (Mini Cooper**).
'g'+'e'+'mini'='GEMINI'
(Other definitions for gemini that I've seen before include "lot of stars" , "House" , "Zodiac sign - the Twins" , "Sign of the Twins ( 6)" , "set of twinklers" .)