Vehicle climbing in distance makes you wonder (7)
I believe the answer is:
miracle
'wonder' is the definition.
(thesaurus)
'vehicle climbing in distance' is the wordplay.
'vehicle' becomes 'car' (car is a kind of vehicle).
'climbing' says the letters should be written in reverse (in a down clue, letters climb up).
'in' indicates putting letters inside.
'distance' becomes 'mile'.
'car' reversed gives 'rac'.
'rac' put within 'mile' is 'MIRACLE'.
'makes you' is the link.
(Other definitions for miracle that I've seen before include "Extraordinary event" , "Remarkable occurrence" , "Supernatural act of God" , "It's said to happen by the divine intervention" , "Inexplicable wonder" .)