One polished with endless care? (3)
I believe the answer is:
car
'one polished with endless care?' is the definition.
'car' can be an answer for 'care?' (car care is a kind of care). I'm not certain of the 'one polished with endless' bit.
'endless care?' is the wordplay.
'endless' means to remove the last letter.
'care' with its final letter removed is 'CAR'.
Can you help me to learn more?
(Other definitions for car that I've seen before include "4-wheeled vehicle" , "Means of transport" , "Hatchback, say?" , "Railway carriage; vehicle" , "One for the road?" .)