Something big crashes into microcar I bought (7)
I believe the answer is:
caribou
'something big' is the definition.
(large animal)
'crashes into microcar i bought' is the wordplay.
'crashes into' indicates a hidden word.
'CARIBOU' is hidden within 'microcar i bought'.
(Other definitions for caribou that I've seen before include "Wild animal" , "N.American reindeer" , "Reindeer of North America" , "Large North American deer" , "N. American reindeer" .)