Sound coming from car, old (5)
I believe the answer is:
audio
'sound' is the definition.
('audio' can be a synonym of 'sound')
'car old' is the wordplay.
'car' becomes 'audi' (audi is a german car brand**).
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'audi'+'o'='AUDIO'
'coming from' acts as a link.
(Other definitions for audio that I've seen before include "Prefix indicating hearing or sound" , "Sound recording" , "Reproduced sound" , "shown in reproduction" , "- - visual aids" .)