Final answer:
When U.S. consumers prefer Toyota trucks to Ford trucks, the net export curve shifts to the left.
Step-by-step explanation:
When U.S. consumers decide that they prefer Toyota trucks to Ford trucks, the net export curve shifts to the left. This is because U.S. consumers are now buying more Toyota trucks, which are imported from Japan, and fewer Ford trucks, which are made domestically. The decrease in demand for Ford trucks reduces the country's net exports, leading to a leftward shift in the net export curve.