Volkswagen buzzer let loose (6)
I believe the answer is:
beetle
'volkswagen' is the definition.
(Volkswagen Beetle is a model of car)
'buzzer let loose' is the wordplay.
'buzzer' becomes 'bee' (something that buzzes).
'loose' indicates anagramming the letters (letters are loosened from their original positions).
'let' with letters rearranged gives 'tle'.
'bee'+'tle'='BEETLE'
(Other definitions for beetle that I've seen before include "8's (very small) friend" , "Lee bet he could be an insect" , "Volkswagen car" , "pest" , "Insect with hardened forewings - scurry" .)