A snack in the car? (5)
I believe the answer is:
rolls
'the car?' is the definition.
(short for Rolls Royce)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for rolls that I've seen before include "Small rounded bread pieces" , "Moves by turning" , "Some bread; trills (an r)" , "Luxury car - lists of names" , "Overturns -- luxury car" .)