Is there a size limitation on an advertisement displayed in the back window of my vehicle?

Question:

I recently had the privilege  to ride in a car that’s  rear window had a full blown textured advertisement on it.

To my shock I discovered that if the sun shines on the rear window I can see nothing.

When I tried to reverse I found that unless I can see an object directly behind me, I could in fact not see where I am going.

Now I notice it is now common practise for businesses to advertise like that, is this not contravening above regulation?

I am just wondering, because my observation now is that I notice drivers with rear windows like that seem to have

Problems with navigating the road.

Answer:
It is illegal to have an advertisement that covers more than 1/8 of the rear window.

Alta

Alta Swanepoel & Associates