That's an... interesting question!
Unfortunately, it's not possible for a poop to propel a car. Poop is a biological waste product that doesn't have the physical properties or energy density to generate the thrust needed to move a vehicle.
Cars require a significant amount of energy to move, which is typically provided by burning fossil fuels, electricity from batteries, or other forms of propulsion like hydrogen fuel cells. The energy released from a poop would be negligible compared to what's required to propel a car.
Additionally, the physical properties of poop wouldn't allow it to generate the necessary force or speed to move a vehicle. Poop is a soft