Customers having a change of heart in Cowes (5)
I believe the answer is:
coves
'customers having a' is the definition.
I can't judge whether this defines the answer.
'change of heart in cowes' is the wordplay.
'change' becomes 'even' (evening is a kind of changing).
'of heart' means to look at the middle letters (I've seen 'heart of' mean this).
'in' indicates putting letters inside.
'cowes' becomes 'cos' (I can't justify this - if you can you should give a lot more credence to this answer).
The middle letters of 'even' are 've'.
've' put within 'cos' is 'COVES'.
Can you help me to learn more?
(Other definitions for coves that I've seen before include "Small bays, fellows" , "Sheltered bays" .)