Go their separate ways back to the vehicle (4)
I believe the answer is:
part
'go' is the definition.
(I've seen this in another clue)
'their separate ways back to the vehicle' is the wordplay.
I cannot quite see how this works, but
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is present in the answer.
The remaining letters 'par' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for part that I've seen before include "Piece; divide" , "Fraction of the whole - separate" , "Divide; role" , "Component; divide" , "Some - theatrical role" .)