New data released by the China Passenger Car Association earlier on Monday show that China's peak car-buying season hit the brakes, with September passenger-vehicle retail sales plunging 28% from a year earlier as manufacturers increasingly relied on overseas buyers to cushion soft domestic demand. The CPCA said in the report that retail sales fell to 1.62 million vehicles, marking a 12th consecutive monthly decline from a year earlier. Sales rose 5% from August. The report showed that electric cars and plug-in hybrids accounted for a whopping…