Anyway it's where the customs may look (2,3,4)
I believe the answer is:
in any case
'anyway' is the definition.
(I know that anyway can be written as in any case)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for in any case that I've seen before include "Whatever the facts are, whatever happens" , "Where customs officers may search" , "Whatever the facts are, one way or the other" , "No matter what" , "At all events" .)