Non-stop talker on car journey? (10)
I believe the answer is:
motormouth
'journey?' is the definition.
I don't know anything about this answer so I cannot tell whether this works.
'non-stop talker on car' is the wordplay.
'non stop talker' becomes 'mouth' (I can't justify this - if you can you should believe this answer much more).
'on' means one lot of letters go next to another.
'car' becomes 'motor' (motor can informally mean a car).
'mouth' put after 'motor' is 'MOTORMOUTH'.
Can you help me to learn more?
(Other definitions for motormouth that I've seen before include "Non-stop chatterbox" , "Constant talker" , "Someone who won't shut up" .)