Complain about the automobile parking? (4)
I believe the answer is:
carp
'complain' is the definition.
(carp can informally mean to complain or whinge)
'the automobile parking?' is the wordplay.
'the automobile' becomes 'car' ('car' can be a synonym of 'automobile').
'parking?' becomes 'p' (abbreviation on road signs).
'car'+'p'='CARP'
'about' acts as a link.
(Other definitions for carp that I've seen before include "Go on at" , "Fish < and beef" , "Large freshwater fish" , "ish" , "Fish - make captious criticism" .)