WASHINGTON — Three days before a U.S.-China summit, the top U.S. trade official is blasting Beijing for imposing “egregious” taxes on American-made cars. In a statement Wednesday, U.S. Trade Rep. Robert Lighthizer complained that China slaps 40 percent tariffs on U.S. auto imports — more than the 15 percent tariffs it imposes on other countries and the 27.5 percent U.S.