Loose car seat on trip causes delay (13)
I believe the answer is:
procrastinate
'delay' is the definition.
(I know that procrastinate is a more specific form of the action delay)
'loose car seat on trip' is the wordplay.
'loose' is an anagram indicator (letters are loosened from their original positions).
'car'+'seat'+'on'+'trip'='carseatontrip'
'carseatontrip' with letters rearranged gives 'PROCRASTINATE'.
'causes' is the link.
(Other definitions for procrastinate that I've seen before include "Dilly-dally" , "Put off till later" , "Postpone" , "Be dilatory" , "Defer action" .)