I have minor surface rust all over the underbody. It's not bad, just flaky areas, especially in some cavitys where you can't get your hand to sand or clean. how would you cover that up? If it has dirt AND paint all around it? And where can I get this stuff? I have checked all the auto parts stores and even asked around. No one has even heard of it. Is this another Zaino like deal where you can only get it online?