When we model position of things in code, we often put the position within the thing being modeled - car, game character, window, etc. So you can do things like: aCar.position - but I think that might be conceptually wrong and have been thinking that for a long time but haven't had much chance to explore the idea.

But of course, you can have this API and delegate the responsibility of calculating the position:

   class Street {
       has 'cars';
       method add_car(){
           $car = Car->new( street => $self );
           $self->cars->add($car);
           return $car;
       }
    }

    class Car {
        has 'street';
        method position() {
            $self->street->position_of($self)
        }
    }

Now, given a random Car, you can still ask "$car->position", but the actual calculation is handled by something else.

(The deeper issue here is how consumers of Car are not coupling themselves to a particular position-calculation strategy. Change the storage of the position value from the Street to the Car, and consumers are none the wiser. This is the point of OOP.)