Carbon footprint? Really? How many cars have been built, driven and scrapped since 1964. By keeping the old iron on the road and not sending it to be crushed and being turned into a tesla,that car has done a lot less harm to our enviroment.1/100th of a new car. Moreso if its comparing to the salted highway type of car. A fine tuned automobile the adding a cat wont change a thing. Except burn more gas.