New models thus produced are of rare quality (6)
I believe the answer is:
seldom
'thus produced are of rare quality' is the definition.
I can't judge whether this defines the answer.
'new models' is the wordplay.
'new' is an anagram indicator.
'models' anagrammed gives 'SELDOM'.
Can you help me to learn more?
(Other definitions for seldom that I've seen before include "Alluvium" , "on rare occasions" , "Not very often, rarely" , "Once in a blue moon" , "Models (anag)" .)