Japan's domestic sales of new vehicles rose 18.7 percent year-on-year to 254,464 units in December for the fourth consecutive month of growth, the Japan Automobile Dealers Association said Monday.Among Japan's top three automakers, Toyota Motor Corp. sold 102,566 new cars, down by 11.8 percent, while Honda Motor Corp's sales more than doubled to 38,767 units thanks to strong demand for its next-generation hybrid mode, and Nissan Motor Corp. saw a 1.0 percent growth to 31,420 units.For the full year, sales of registered vehicles, which exclude mini-cars or mini-trucks fell 3.8 percent from a year earlier, due to the termination of a government subsidy last September for the purchase of eco-friendly vehicles, the association said.