Japanese automakers are being forced to ship some car parts to U.S. plants by expensive air cargo and tweak production processes as a protracted labor dispute at U.S. West Coast ports shows no signs of letting up. Fuji Heavy Industries Ltd’s Subaru, the fastest-growing brand in the United States, said this week that it now had to shoulder an extra 7 billion yen ($60 million) in costs a month due to air freight, which has seen prices go up with the extra demand.