back of envelope calculations
seoul, south kr -> long beach, ca = 6000 miles
inland barge offers 514 ton-miles / gallon of fuel (http://www.arc.gov/index.do?nodeId=2571)

hyundai elantra curb weight = 2522 lbs = 1.25 tons

assuming a panamax or cape sized cargo ship gets roughly same eff as a barge (??), then it required 14.6 gallons of fuel to ship an elantra here. If a cargo ship is 25% as efficient as a barge, then it only cost 60 gallons of fuel to get it to long beach.