 In April 2013, Metro elected to exercise an option in the contract to purchase an additional one hundred cars to replace its one hundred 4000-series cars, which it decided do not warrant being overhauled in light of chronic mechanical issues.In September 2013, Metro announced it exercised another option under the contract to purchase an additional 220 7000-series railcars, bringing the total order to 748 railcars.In total, the new 7000-series railcars will make up more than half of Metro's rolling stock by 2020.