Vehicle includes a structure defining an interior space for containing or designed to contain one or more objects, and an arrangement mounted on, joined or coupled to the structure for determining whether an object is present in the interior space, or the presence of multiple objects. One arrangement includes at least one optical imaging device arranged to receive images of the interior space defined by the structure, and a processor coupled to the optical imaging device(s) and arranged to determine whether one or more objects are present in the interior space and when one or more objects are determined to be present, to obtain information about the object or objects. The processor is preferably arranged to distinguish between different objects and/or different arrangements of objects. A related method for obtaining information about objects in interior spaces of vehicles is also disclosed.