Dashboard is loud, like spies (6)
I believe the answer is:
fascia
'dashboard' is the definition.
(I've seen this before)
'loud like spies' is the wordplay.
'loud' becomes 'f' (short for forte - 'loud' in music).
'like' becomes 'as'.
'spies' becomes 'CIA' (Central Intelligence Agency).
'f'+'as'+'cia'='FASCIA'
'is' is the link.
(Other definitions for fascia that I've seen before include "Flat strip on shop front for name etc" , "panel" , "Surface over shop window" , "Shop sign" , "Car dashboard" .)