The law in question has the direct qualifier that the material is attached to a motor vehicle, which seems to imply a specific purpose. Based on the traffic law

The law in question has the direct qualifier that the material is attached to a motor vehicle, which seems to imply a specific purpose. Based on the traffic laws in my own country it seems strange to list specific items like that rather than intent, which from what I would guess is that drivers should not attach things which will distract other drivers and potential cause an accident. If this happened here the chain of events would look somewhat like this: The police would stop the driver and inform them of the distracting attachment, possible giving a fine. If the driver refused to remove the sticker then the police would simply revoke the drivers license and impound the car. If the driver tried to resist they would go to jail over that and/or driving without a license. The driver can then choose to appeal the decision and have a court decide if the attachment was too distracting or not.