Technology

this number is so far off that it makes me doubt your whole story...

quick estimate: if we assume your teacher had a rather new car with good fuel economy (6l/100km) and was using only the least polluting fuel (e85 with 15% ethanol that produces some 1.6kg of co2 per liter) we would have to assume it was a really heavy car made entirely out of the stainless steel (1500kg of the most poluting steel that produces over 6kg of co2 per kg of steel, other materials have comparatively small contribution) to come anywhere close... about 10 tons of co2 from car production and from burning the fuel.

from these crazy assumptions you can easily see that most normal vehicles under normal circumstances will produce way more (like order of magnitude more) of co2 by driving than is produced by making them. for example a smaller car made from 600kg of normal steel (1.8kg of co2 per kg of steel) and fuel efficiency of 8l/100km (still very good) will produce more co2 than was produced in its own production after roughly 5000 miles of driving and is just adding after that...