You mean that the automakers fought the government from telling them what to build. This is natural and understandable. Not only because government telling them what to offer in their products is fundamentally wrong, but that they had tried to sell safety before and it wouldn't sell.
The idea that automakers didn't care for safety and didn't want to provide it is incorrect and any fair examination of history of the industry shows that. I've seen films of Henry Ford demonstrating laminated safety glass, the safety of the Chrysler Airstream, the benefits of GM's new braking systems in the 1930s, and much more. There has always been a drive to make safer vehicles and get the public to buy them.
However, the public didn't really start listening until the 80s. Then again, perhaps it had to do with the funds people had available to them, making safety a lower priority until their incomes increased or automakers increased productivity to where such things were affordable.
If at any time the car buying public had demanded safety devices the automakers would have provided them immediately. Many were *OPTIONS* for years before government made them required. They were options because most people wouldn't buy them back then.
Airbags are a prime example. Offered on expensive big three passenger cars in the early 1970s they weren't purchased often and problems were discovered with regards to children and small adults in using them to stop unbelted passengers. The government regulators refused to listen in the 1980s and the result was needless deaths from airbags designed to stop an average unbelted male.
What really needed to happen wasn't the growth of the government and using government force, but education of the american car buyer. All the safety regulations could evaporate right now and approximately nobody is going to knowingly buy a car that isn't as safe as we have come to know cars to be. That education has happened, all the government force didn't really make cars safer, it was the buyers demanding it. Government gets in the way right now with its CAFE requirements since today's buyers care far less about fuel economy than they do safety. While the government is more the reverse these days.