Scrap of cloth used in garage (3)
I believe the answer is:
rag
'scrap of cloth' is the definition.
(I've seen this before)
'in garage' is the wordplay.
'in' indicates the answer is hidden within the clue.
'RAG' can be found hidden inside 'garage'.
'used' acts as a link.
(Other definitions for rag that I've seen before include "Student event" , "Student carnival for charity" , "charity event" , "Play practical jokes on - worthless newspaper" , "Student fundraiser" .)