Bucket of bolts (6)
'bucket of bolts' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for jalopy that I've seen before include "Old and unreliable car" , "Old vehicle" , "wreck" , "Rundown old car" , "Ramshackle old car" .)
(Other definitions for junker that I've seen before include "Foreign aristocrat" , "one having a clearout?" .)