For Cars 2, I know four other retro style posters were designed by Eric Tan. Bruce sold one set not long ago for a little bit over $200 (
http://www.emovieposter.com/agallery/archiveitem/5437366.html). I talked to him, but he didn't know for sure the origin of the poster. So I contacted the artist, Eric Tan, and I just receive the reply from him last weekend, quoting:
"
As far as the Cars posters, what you have are the 4 that were used for public marketing. They were pasted up on walls around a few cities a couple of months prior to the film release. I'm not really sure how many were actually printed but I don't think they made them available to the public to purchase or collect."
As for the availability of the posters, according to Eric, the ones measured 19x27 are never made available for public, while there are some commercial giclee ones with limited number, e.g.295, measured 13x19 on paper or 17x24 on canvas and priced $155, $425 each, respectively. This is all I know. Actually, there are even some other retro designs, but I'm not sure they are available anywhere or not, like this one (
http://erictanart.blogspot.com/2011/04/and-more-cars.html).
That looks like on of the internal posters Pixar do for their releases. I visited their offices when UP was coming out, and the main hall was decorated with fake vintage travel poster advertisement for the different places mentioned in the movie. They were beautiful! It might be that they sold some of them in the gift shop, but most I think were one-offs. It is just one of many things they do to increase immersion in the movie world. They probably did the same for CARS 2. Where did you get it?