Rogue put Kildare reg on retro vehicle (5)
I believe the answer is:
knave
'rogue' is the definition.
(I know that rogue can be written as knave)
'reg on retro vehicle' is the wordplay.
'reg' becomes 'ke' (I am not sure about this - if you are sure you should believe this answer much more).
'on' means one lot of letters goes inside another (as in clothing 'on' a person).
'retro' shows that the letters should be reversed in order (retro is Latin for 'backwards').
'vehicle' becomes 'van' (type of vehicle).
'van' reversed gives 'nav'.
'ke' going around 'nav' is 'KNAVE'.
'put kildare' acts as a link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for knave that I've seen before include "cheat of old" , "Jack - the cad!" , "Jack in a pack of cards" , "geezer" , "[COURT CARD] , maybe" .)