Vehicle caught in rainstorm from heaven (7)
I believe the answer is:
nirvana
'heaven' is the definition.
(synonyms)
'vehicle caught in rainstorm' is the wordplay.
I cannot quite understand how this works, but
'vehicle' could be 'van' (van is a kind of vehicle) and 'van' is found within the answer.
This may be the basis of clue (or it may be nonsense).
'from' acts as a link.
(Other definitions for nirvana that I've seen before include "Buddhist blessed extinction" , "religious ecstasy" , "Ultimate tranquil state" , "State of pure happiness" , "Eastern place of complete bliss" .)