carbon dioxide as far as I know.
Cars put a chemical in the air through their exhaust pipe called carbon monoxide.
Cars do indeed produce exhaust, but they are not the only source of exhaust which can come form other forms of transport, house boilers and factories.
Cars do not have anything in their exhaust to reduce carbon monoxide. A Catalytic Convertor in the Exhaust System is used to remove Carbon Monoxide from the exhaust gasses.
exhaust is spewed from cars and trucks.
Exhaust
No cars do not have wood in them. Metal iron and other material but not wood. Heat comes from cars so a car would start on fire from the exhaust. But Derby cars for boy scouts would. US automobile manufacturers stopped using wood in the early 1950's.
Improve appearance
to decrease exhaust noise
yes
When Exhaust brake is on squeak noise comes from the engine?"
because your gas tank is in the center
Exhaust fumes from cars are an example of air pollution. They contain harmful gases and particulate matter that are released into the atmosphere, contributing to environmental and health issues.