Because car Hitler looks like Hitler, in the shape of a car he would use. Hence the 6 wheel Mercedes-Benz. Because that is the car most associated with Hitler. What that has to do with a race he most liked, I don't know. That's like saying it looks nothing like a painters easel (Hitler was an artist by trade) so it's not Hitlers car. Or because it looks nothing like Austria (or an Austrian car maker).
Also, Hitler was many, many, many things, but hypocritical was none of them. He never claimed to Aryan. He never even claimed to be German. None of his senior staff were Aryans either. He claimed the supremacy of the Aryan race and worked to set Germany / Europe up as a place for them, but never claimed ownership or membership.