Holy person has posh car? Walks! (7)
I believe the answer is:
strolls
'walks' is the definition.
(strolling is a kind of walking)
'holy person has posh car?' is the wordplay.
'holy person' becomes 'st' (short for saint).
'has' is a charade indicator (letters next to each other).
'posh car?' becomes 'rolls' (short for rolls royce).
'st'+'rolls'='STROLLS'
(Other definitions for strolls that I've seen before include "Walks" , "Ambles" , "Takes a turn" , "Saunters" .)