Car worker, a successful TV show contestant? (5,6)
I believe the answer is:
panel beater
'car worker' is the definition.
'a successful tv show contestant?' is the wordplay.
I cannot really understand how this works, but
'a' could be 'an' and 'an' is found within the answer.
'show' could be 'er' (US medical drama) and 'er' is found within the answer.
This may be the basis of the clue (or it may be nonsense).
(Other definitions for panel beater that I've seen before include "Body builder perhaps" , "Car body worker" , "who did well on What's My Line?" , "triumphant on What's My Line?" , "Garage worker" .)