The technological difference between the cars is completely and totally beside the point. It's not as if the consumer has the choice of buying a 2005 car in 1964. He buys what is in front of him. He buys a car from a category, in this case, economy coupe. And the purchase price of the economy coupe has remained the same (and that probably goes across the board for all categories of cars. The first Mustang was about 5k. Multiply it by six and you get close to what a Mustang costs now.). Whether it is the same physical car is immaterial to the purchase price over time.
And whether the purchase price is a higher percentage of my income now than then does nothing to enrich GM. They are getting the same money. Saying they have raised prices by lowering my disposable income makes no sense.
Now if I am less able to purchase something for the same price today than I was forty years ago, it obviously means I don't have as much money to spend as I did then.
That simply makes no sense. One cannot argue that real incomes are falling because contemporary cars are more "expensive" than "historical" cars, and when it's pointed-out that a contemporary car is dissimilar to a historical car, claim it's "immaterial."
Or it means that you are unwilling to buy more car as you did previously.
So you think that you should get more items on a car and then pay the same for it? You've gone absolutely mad.
People WANT these so-called "luxury" items on cars. They are willing to pay for them, clearly, because there are no cars that don't have them on there.
If GM made a car that didn't had a 40 hp engine and no power steering and no power brakes and no ABS and no a/c and no padded dash and no seat belts and no air bags and no automatic transmission and no front/rear crumple zones and no side impact door beams, it might sell for $5000, which would be less than your VW Beetle. But the long and the short of it is that people don't want cars without that stuff, so they pay more--which we've already established that they do.