The future of cars is likely to see a transition from petrol and diesel to electric and hydrogen fuel cell vehicles, although internal combustion engines will remain prevalent due to their energy density. While petrol won't run out for another century, prices will continue to rise, prompting a shift towards diesel and biodiesel. Water is not a fuel but can be a source of hydrogen when split into its components, though the energy required for this process exceeds the energy gained from burning hydrogen, making it inefficient. Discussions highlight the potential for hybrid vehicles and biofuels as interim solutions, while acknowledging the challenges of infrastructure and costs associated with electric and hydrogen vehicles. The conversation also touches on innovative concepts for future cars, emphasizing the need for energy-efficient manufacturing and operation.