Let's power a car with a battery that burns so hot and so persistently, that piercing said battery caused firefighters not to bother with extinguishing the car at all.

Let's power a car with a fuel refined from oil extracted at the cost to the environment. Burning it will also cause excessive emissions. Also it will be extremely volatile so the infrastructure to move the fuel and refuel the vehicle will need to be monitored at every point, and it requires fuel to be cooled down to very low temps when it's hot outside.

Let's power a car with natural gas. It's an incredibly toxic chemical that needs to be stored under pressure. It also makes it so you can't park in underground parking since it malfunctioning can lead to people suffocating, or an entire building exploding.

You can always make something sound bad.