A company that spun out of the auto rut .

Meet one of the little companies that could. And did. The Donnelly Corporation may be an unknown name to you, but for an idea of its line, look into your car's rearview. If you have an American-made car, it almost certainly has Donnelly mirrors. And Donnelly has a good chunk of the Japanese market via an Irish plant.

Donnelly stands much of the accepted wisdom about Michigan's small manufacturers on its head. It has diversified away from the automobile industry, but its auto business has continued to grow. It felt the auto industry downturn, but its basic recipe for recession-proofing is growth, with market share increasing across the business cycles. The sales of this privately held company are estimated to have multiplied tenfold over the past 15 years or so, to around

With its own engineering and testing capabilities, Donnelly focuses on sophisticated glass and coating technologies, including the glass used in liquid crystal displays. ''We're technology-driven, not market driven,'' explains James A. Knister, vice-president.

This nonunion company is also noted for its participative management, which won Donnelly a place in the book ''The 100 Best Companies to Work for in America.''

''Our books are always open to employees to inspect,'' reports Kay Hubbard, systems manager. ''Once we had to redo a whole bonus-check payroll because one of the employees had already calculated what his check should be, and when he got it, he knew it was wrong.''