I'm in the San Diego area, everything has shown up except the Fabrizio case, and Taia & Taco.  (At least to my knowledge and the few collectors I talk to)

Exactly the same in the NYC metro area. Taia and Taco were only released overseas. The only ones I haven't seen at retail were the case N with Fabrizio.
I'll say this though; how and how much you Cars hunt determines what and how much you find. In many areas Cars hunting is competive. You really need to get to the stores when new stock comes in.
There are many people near stores friends and I hunt at who probably believe these stores never get anything new or rare, when that's not the case at all. It's just that myself or other people but everything good right away.
So if you don't consistently check a bunch of stores at the right times you probably won't find many good cars anywhere. Those Walmart 2 packs were a good example. I found many dozens of cases and even 2 diplays of them for no more than a week or two and than they were gone forever.

I can actually say that there isn't a Cars 1 release that I hadn't found in the wild.  Some were harder to find than others, I think I only saw GGG at two stores and I only saw Becky and Officer at one store.  Everything else I've found and bought 8-10 or more, with Prince Wheeliam being the most, at one time I had 21 of them.