Did we misread the market news? No, there it was in black and white. Overall new car sales in the United States in 1981 were the weakest in 11 years. Of the US firms, only - now, here it comes - the Chrysler Corporation reported a sales gain for the year. Which all goes to show that with a little bit of grit, hard work, solid product - not to mention generous support from banks, taxpayers, and the federal government - it is possible to register some gains even under difficult economic circumstances.