A new coat, notice (3,5)
I believe the answer is:
wet paint
'notice' is the definition.
I don't know anything about this answer so I cannot tell whether it can be defined by this definition.
'a new coat' is the wordplay.
'a new' becomes 'wet' (I am not sure about this - if you are sure you should believe this answer much more).
'coat' becomes 'paint' (painting is a kind of coating).
'wet'+'paint'='WET PAINT'
Can you help me to learn more?
(Other definitions for wet paint that I've seen before include "Post-decorating notice" , "A fresh coat - twin tape (anag)" .)