Complains: parking clamps ultimately put on wheels (5)
I believe the answer is:
carps
'complains' is the definition.
(I've seen this in another clue)
'parking clamps ultimately put on wheels' is the wordplay.
'parking' becomes 'p' (abbreviation on road signs).
'ultimately' suggests the final letters.
'put on' is a charade indicator (letters next to each other) (some letters go on or after others).
'wheels' becomes 'car' (wheels can informally mean a car).
The last letter of 'clamps' is 's'.
'p'+'s'='ps'
'ps' after 'car' is 'CARPS'.
(Other definitions for carps that I've seen before include "Finds fault with" , "Makes trivial objections" .)