Repository for wrecked car (rear end missing), perhaps (9)
I believe the answer is:
scrapheap
'repository' is the definition.
Although both the answer and definition are singular nouns, I don't see how one could define the other.
'wrecked car rear end missing perhaps' is the wordplay.
'wrecked' indicates an anagram.
'rear end missing' means to remove the last letter (the letter at the rear of the word is removed).
'car' with its last letter taken away is 'ca'.
'ca'+'perhaps'='caperhaps'
'caperhaps' is an anagram of 'SCRAPHEAP'.
'for' acts as a link.
(Other definitions for scrapheap that I've seen before include "Where unwanted items end up" , "Place for useless or redundant people or things" , "Waste pile" , "metal tip" , "Junk" .)