While the 2015-2020 Mustang downsized its quarter window area compared to the S197s, there is still enough of room to fit a pair of scoops or louvers and give your Pony an aggressive new look or some old-school cool like the '60s era fastbacks. Quarter window scoops and louvers are simple, yet extremely effective styling upgrades that really bring out the best of your 2015-2020 Mustang's aggressive lines and contours. When you're done here, check out our selection of 2015-2020 Mustang Hoods for a dramatic front-end upgrade.