Even though he had such preferences, Earl was not a slave to them, particularly the rounded look. After 1935 or thereabouts when the appearance of streamlining became the norm for American automobile style, his GM cars had curves, but there were usually crisp or angular surfaces and details that contrasted or complemented the curved parts.
An interesting example of Earl's styling ideals is the design of the 1949 Buick. I think its styling can be characterized as being a series of curves cascading from the high point of the car's top.
I don't consider the 1949 Buick a great design. But for its era, it is a good one. For some reason, the cascading curves theme has always appealed to me even though I suspect that it is not a good general-purpose design practice. That's because it would usually yield a too-soft appearance. 1949-vintage cars tended to look a little soft anyway, perhaps due to the state of sheet metal stamping practice, so the Buick design theme works well in that context.