Car blue, in one sense? (8)
I believe the answer is:
auditory
'one sense?' is the definition.
(auditory sense is a kind of sense)
'car blue' is the wordplay.
'car' becomes 'audi' (audi is a german car brand).
'blue' becomes 'tory' (I've seen this in other clues).
'audi'+'tory'='AUDITORY'
'in' is the link.
(Other definitions for auditory that I've seen before include "as one hears" , "Via the ears" , "Relating to hearing" , "Related to the sense of hearing" .)