According to the mid-year R.L. Polk & Co. Automotive Loyalty Award rankings released Monday, Aug. 12, for the first half of the 2002 model-year, General Motors had the highest percentage of loyal customers of any automaker that sells vehicles in the United States. R.L. Polk's study of vehicle registration data showed that 68.5 percent of people who bought or leased a GM vehicle in the 2002 model year previously had bought or leased a GM vehicle sometime in the past 10 years. R.L. Polk, a Southfield, Mich., data collection, analysis and marketing firm, defines loyalty as a household that buys or leases a new vehicle of the same model, make or manufacturer as they had bought or leased in the past 10 years. The information is based on vehicle registration data. The study produces rankings for 14 categories.