The 2007 and later Dodge Caliber has Ultra-High Strength Steel UHSS in the A-pillar, B-pillar, and roof-rail reinforcements. The B-pillar is made from a tailor-rolled, hot stamped steel which would tell you that the pillar will have different thicknesses. The two-piece pillar includes a lower section made from mild strength steel, and is combined with a tailor-rolled ultra high-strength steel upper section.
Just in case you were wondering what a Tailored-rolled steel is, here is the answer. A flat piece of metal that is stamped into a part is called a blank. A Tailored blank combines different thicknesses and grades of steel into a single blank.