Trouble with a car key (4)

I believe the answer is:

care

'trouble with' is the definition.

'a car key' is the wordplay.
'key' becomes 'e' (I've seen this in other clues).
'car'+'e'='CARE'

(Other definitions for care that I've seen before include "Race (anag.)" , "Caution; keeping" , "Have concern or regard" , "The provision of what's necessary, for health say" , "Worry" .)

I've seen this clue in the Evening Standard.

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