First to move the panel, shifting piece of junk (5,8)
I believe the answer is:
white elephant
'piece of junk' is the definition.
(white elephant can mean a troublesome possession)
'first to move the panel shifting' is the wordplay.
'first to move' becomes 'white' (white moves first in chess).
'shifting' is an anagram indicator.
'the'+'panel'='thepanel'
'thepanel' with letters rearranged gives 'elephant'.
'white'+'elephant'='WHITE ELEPHANT'
(Other definitions for white elephant that I've seen before include "Possession that proves expensive to keep and difficult to get rid of" , "It gives more trouble than it's worth" , "Opening player" , "conspicuous failure" , "waste of space" .)