Driving at 30 to 40 mph, after over took a car, then released the gas, engine stared to rev high then a sudden and hard pump. It felt like someone hit me from behind. Almost like the transmission came back in gear when the engine was revving high. Engine should not have revved high and with no acceleration of car.

Car is driving ok, dealer says unless there is a error code they can't do anything.

This to me is a safety item and needs to be IMMEDIATELY looked at by Hyundai...