What is the version of the following sentence with correct punctuation?

Even a hybrid vehicle will emit over the course of a year on average nearly 18 tons of CO2 Even if you only commuted to the store and work during the warm months of the year you could cut your cars carbon footprint by half
Even a hybrid vehicle will emit, over the course of a year, on average, nearly 18 tons of CO2. Even if you only commuted to the store and work during the warm months of the year, you could cut your car's carbon footprint by half.