Marvel as vehicle reversed in distance (7)
I believe the answer is:
miracle
'marvel' is the definition.
(thesaurus)
'vehicle reversed in distance' is the wordplay.
'vehicle' becomes 'car' (car is a kind of vehicle).
'reversed' shows that the letters should be reversed in order.
'in' is an insertion indicator.
'distance' becomes 'mile'.
'car' back-to-front is 'rac'.
'rac' inserted inside 'mile' is 'MIRACLE'.
'as' acts as a link.
(Other definitions for miracle that I've seen before include "Supernatural happening" , "Supernatural occurrence" , "Remarkable and welcome event" , "Extraordinary event" , "Saintly deed" .)