Maybe you meant something like this?
Do you think this person might have a commercial interest in an opposing point of view? Since he's selling an alternative product? Hardly an unbiased or objective source. And since the rubberized undercoating sold currently is really a heavy duty primer with binders and just a little bit of rubber in it how is the water going to get underneath it? Ziebart is a totally different product and also by the way no longer used anymore. How exactly do you get water trapped underneath and through primer that is waterproof by the way?