Kia or Cadillac (4)
I believe the answer is:
auto
'kia or cadillac' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for auto that I've seen before include "Drama" , "Car (mostly US)" , "Lincoln?" , "Prefix denoting by or of the same person or thing" , "Prefix meaning self or same" .)