Pickups have more places to put little flagpoles.
I can think of a few big car - small car - big car - small car cycles over the last 30 years, and as insane as it sounds, GM is not entirely unreasonable in assuming "this will pass".

And, I believe studies during the Great Depression showed that people will give up everything possible before giving up their car or the gas for it.

Don't have the data, but if I remember from classes wasn't per capita distribution light?  I remember the roaring 20's (the setup) and even at it's height car ownership was still a great status enjoyed by a few(including those ford workers paid enough to buy them, there were only so many of them too).  Just curious though.
While not the saturation it's at now in the US, I think by the 1930s car ownership was pretty high. Ford had been producing like crazy through the 1920s, had lowered and lowered the price of the T, and the other makers had all been producing like crazy in the 1920s also. Remember the 1920s were a period very much like our own - widening between the rich and poor, real estate speculation, tons of buying on credit, they were one big party - the 1930s were the hangover.

Ever read Archie Comics? They were written about the high school experience in the 1920s. It was a given that high school students had a car if they wanted one, even if it was a beat up old T like Archie had.

A minor correction: The timeframe the characters from "Archie Comics" inhabit is the late 1940's. Immediate post-war period.
Wow really? I read somewhere it was based on the creator's experiences in HS in the 1920s.
That may be true, however the first Archie comic wasn't produced until 1941.
http://www.archiecomics.com/news/pr060206_anniversary.html
Most of the inanimate items in the comics date from the 1940's (from black and white be-bops to roadsters and drive-ins).
Well, if the guy who came up with Archie comics went to HS in the 1920s, he'd be in his 40s or so in the 1940s and started the strip then. I think it was not only a neat and cute strip, but had some appeal as a nostalgic thing, looking back to those good times in the 20s which is understandable after the Depression, WWII, and the recession the US was in right after WWII.

Then, some "modern" things like drive-ins added to make it not seem too much of a nostalgia trip. Besides that, a lot of those things were first come up with in the 1920s. They just got big in the 1940s-50s.

OK, looks like the guy went to Haverhill HS in MA in the 1930s, and started comicking about it in the early 40s.