Train on vehicle which won't bring you back (8)
I believe the answer is:
rehearse
'train on vehicle which won't bring you back' is the definition.
'rehearse' can be an answer for 'train' (thesaurus). I am not certain of the rest of the definition.
'train on vehicle' is the wordplay.
'train on' becomes 're' (I can't justify this - if you can you should give a lot more credence to this answer).
'vehicle' becomes 'hearse' (hearse is a kind of vehicle).
're'+'hearse'='REHEARSE'
Can you help me to learn more?
(Other definitions for rehearse that I've seen before include "Cast practise for play" , "Practice a play" , "Practise like actor" , "Train" , "Practise before performing in public" .)