The 1946-1954 models are often characterized as pre-WWII carryovers, but this was only true for the '46 and '47 models. While '48-'54 was a period before the big styling in '55 and '57, there was lots of innovation during those years. For example, GM's introduction of new high compression, short stroke OHV engines in Olds and Cadillac, plus the '51 Chrysler hemi; torque converter automatic transmisssions by several manufacturers; pillorless hardtop styling; tail fins (for better or worse) on the '48 Cadillac; innovative new styling by each of the independents, including the '54 Kaiser Darrin; and several all-new post-war platforms.
I could go on, but my point is that this was an exciting period for domestic manufacturers. I invite you to add to the list and comment.