I need a hand with driving on vacation – somehow revealing ulterior motive (6,6)
I believe the answer is:
hidden agenda
'ulterior motive' is the definition.
(I've seen this in another clue)
'i need a hand with driving on vacation somehow' is the wordplay.
'with' means one lot of letters go next to another.
'on vacation' suggests removing the centre (after the inside letters have vacated the word).
'somehow' indicates an anagram.
'driving' with its centre taken out is 'dg'.
'i'+'need'+'a'+'hand'+'dg'='ineedahanddg'
'ineedahanddg' is an anagram of 'HIDDEN AGENDA'.
'revealing' is the link.
(Other definitions for hidden agenda that I've seen before include "that could delay the meeting?" , "Ulterior motive" , "Concealed intentions" , "Undisclosed reason" , "covert plan" .)