Stupid because it's right there in the picture but what is that? Did you use both of those cans in that picture?
The "S" word is pretty rude. Try not to use it.
Yes, you have to use both can. Thinner is to rub off the metallic paint. Under the metallic paint is the matt deep red rubber undies. I use the polyglaze to give it back the shine or one may call gloss finish.