US car sales in May are tracking at an annualised rate of 15.8 million, down from 16.4 million in April despite heavy incentives, The Car Connection (TCC) website said, citing Deutsche Bank auto analyst Rod Lache. The website also cited GM sales chief John Smith as saying on Thursday: "so far in May, industry sales are running at a weaker rate than in April, but the pace could pick up as incentives rise."