Polk defines loyalty in terms of new car customer retention: a new car buyer returning to buy another new vehicle of the same make or model.
For the 2005 model year, Toyota enjoyed a 54.6 percent loyalty rating, while 63.1 percent of GM new car buyers bought another new GM car.
Asian manufacturers scored their best result since the survey began 10 years ago, leading five market segments.
Full results are here. Previous survey results can be found here.