Electric car completely prepared to reverse off trail’s end (5)
I believe the answer is:
tesla
'electric car' is the definition.
(I've seen this in another clue)
'prepared to reverse off trail's end' is the wordplay.
'prepared' becomes 'set' (set up or ready).
'to reverse' shows that the letters should be reversed in order.
'off trail's end' becomes 'la' (I can't justify this - if you can you should believe this answer much more).
'set' reversed gives 'tes'.
'tes'+'la'='TESLA'
'completely' is the link.
This may not be right. It may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for tesla that I've seen before include "Inventive sort" , "Californian company specialising in electric cars" , "Unit of magnetic flux density" , "SI unit; steal (anag.)" , "Nikola ---, electricity pioneer" .)