 Complete the following phrase:  Volkswagen does not endorse the proposal under discussion. It places an unfairly high burden on passenger cars, while allowing special compliance flexibility for heavier light trucks. Passenger cars would be required to achieve 5 annual improvements, and light trucks 3.5 annual improvements. The largest trucks carry almost no burden for the 20172020 timeframe, and are granted numerous ways to mathematically meet targets in the outlying years without significant real-world gains. The proposal encourages manufacturers and customers to shift toward larger, less efficient vehicles, defeating the goal of reduced greenhouse gas emissions. Additionally, Volkswagen has since approached U.S. lawmakers about lowering their proposal to double fuel efficiency for passenger cars by 2025. Volkswagen at the time claimed that the new plan was unfair, but the company was later revealed to have been 