Luxury car in outskirts of Derby? That’s funny (8)
I believe the answer is:
'that's funny' is the definition.
'luxury car in outskirts of derby?' is the wordplay.
'luxury car' becomes 'roller' (short for Rolls Royce).
'in' is an insertion indicator.
'outskirts of' says to hollow out the word (remove centre letters) (only letters on the outskirts).
'derby' with its centre removed is 'dy'.
'roller' put inside 'dy' is 'DROLLERY'.
(Other definitions for drollery that I've seen before include "display of humour" , "Comical quality" , "comedy" , "jokes" , "Jesting" .)