Once upon a time, General Motors' mid-sized models were the perennial top-selling passenger cars in America. Within my own lifetime, the Oldsmobile Cutlass topped the sales charts for years on end. But somewhere along the way, it all went pear-shaped for GM. Its cars went from being perpetual sales leaders into a perpetual sales decline. As GM's car sales tanked, the Toyota Camry and Honda Accord picked up the slack and are now considered the standard by which others in the class are measured.