Gone are the days of the three-year car loan. The length of the average automobile loan hit five years, four months in October, up more than six months from 2002, according to the Federal Reserve. And nearly 45% of loans written today are for longer than six years. Even some staid lenders owned by the carmakers, such as Toyota Financial Services and Ford Credit, are offering seven-year financing. And a few credit unions, particularly in the West, are tinkering with the eight-year note.