Assume that these states are included in "mid-west" as well, let's see how many we have ... although would have to say there is a lot of ways this could break out other ways as well ... no single school of thought on this ...
http://geography.about.com/library/misc/blregions.htm
really need to see large concentration of current and future owners; for example the Corvette forum uses:
Illinois | Indiana | Iowa | Michigan | Missouri | Minnesota | Ohio | Wisconsin for their Great Lakes region and then
Colorado | Kansas | Montana | North Dakota | Nebraska | South Dakota | Utah | Wyoming for Mountain/Prairie
both are based on number of members in the regions ... take a look:
(scroll down to regions)
http://forums.corvetteforum.com/index.php?