There were no injuries on the train, authorities said.
The car drove around the crossing gate, witnesses said. The impact threw the car into the air, and the train came to a halt about 300 yards down the track, they said.
"The car is totally demolished," Lakeland police spokesman Jack Gillen said.
The Silver Star was traveling from Miami to New York with 161 passengers aboard, Amtrak spokeswoman Tracy Connell said. The train had stopped in Tampa before the accident.
It was not immediately known how fast the train was going or what caused the accident. The authorized speed for that area is 79 mph.