Houses with 9 or more rooms
30.66% -- Provo-Orem, Utah
29.01% -- Brigham City, Utah
27.12% -- Logan, Utah-Idaho

Households with 3 or more vehicles
37.84% -- Evanston, Wyo.
37.51% -- Blackfoot, Idaho
37.09% -- Gillette, Wyo.

One surprising tidbit, Heber, Utah is in the same list as Jackson, Wyoming for affluent small metros.

"Other small metros that rank in the Top 20 nationally include Juneau, Alaska, Jackson, Wyo., and Heber, Utah, among others."

http://wtop.com/41/3690512/Nations-most-affluent-area-is-