Bump on the rear sounded - little accident (5)
I believe the answer is:
prang
'little accident' is the definition.
'prang' can be an answer for 'accident' (I've seen this before). I'm unsure of the 'little' bit.
'bump on the rear sounded' is the wordplay.
'bump on the rear' becomes 'p' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'sounded' becomes 'rang' (ringing is a kind of sounding).
'p'+'rang'='PRANG'
Can you help me to learn more?
(Other definitions for prang that I've seen before include "Popularly, a motoring contretemps" , "Bomb attack" , "nasty collision" , "Crash involving a car" , "Minor shunt" .)