Vehicles (4)
'vehicles' is the definition.
(car is a kind of vehicle)
This is the entire clue.
(Other definitions for cars that I've seen before include "Automobiles" , "Private vehicles" , "Motor vehicles" , "... when these may be driven?" .)
(Other definitions for vans that I've seen before include "Trade vehicles" , "Commercial vehicles" , "Goods vehicles" , "Transport" .)