Now that is truly a revelation...car manufacurers are outsourcing production of components.
Now please tell us how you came to know proprietary information such as this. How do you know in detail about the component design, bidding and product selection processes of Ford, GM, Chrysler, Toyota, Nissan (and presumably all other car manufacturers in the world). You must be one busy guy to have gained access to so much insider information for so many multinational corporations.
Guess what...even if you knew who made the product you would not know how they were assembled and what products were used. The only way to gain that information would be to sit on the assembly line. Personally, I'm willing to trust the decisions of the people that manufacture cars and spend my time more wisely. Same rule applies to these small fly-by-night filter makers that proclaim their products will outperform any and all comers.