Message on hire car with legible rims (5)
I believe the answer is:
cable
'message on hire' is the definition.
'cable' can be an answer for 'message' (cable is a kind of message). I am unsure of the 'on hire' bit.
'car with legible rims' is the wordplay.
'car' becomes 'cab' (cab is a kind of car).
'with legible rims' becomes 'le' (I am not sure about this - if you are sure you should believe this answer much more).
'cab'+'le'='CABLE'
Can you help me to learn more?
(Other definitions for cable that I've seen before include "Hawser, wire" , "Communications wire" , "Strong suspension bridge made of wire" , "Wire, flex" , "Strong rope made of twisted strands of hemp, nylon or steel wire" .)