In the car's films, some cars have been able to hold objects such as flags so i guess in thhe game they'd make the cars hold things the same way and as for animals they could hold objects in their mouths or as somebody already pointed out they're toys so the objects could float beside them because when you play with toys you find a way to stick items to them you just make them float along side them
![Mr. Green :mrgreen:](./images/smilies/icon_mrgreen.gif)