I have one in my Optima right now, as a matter of fact. They fit perfectly, and seem to work without issue. The Napa Gold had more pleats than the previous filter which was an Auto 7, if memory serves. The filter has been in for almost a year, and it is getting pretty grey, so its capturing something. It might be time to pick one up from Napa myself, especially if they are on sale.
I had to order the filter through my local NAPA. I picked it up the next day. It was in a plain brown cardboard box, with a printed label on it that said noting more than the brand and the part number. The filter itself had Napa Gold and the part number on it. I just thought it was interesting.