This custom 8 inch subwoofer directly replaces the underseat subwoofer found in select BMW models. 200 mm / 8 Car specific subwoofer. 48-6K Hz Freq Response. 1-Series 2009 > 2019. 3-Series 2004 > 2019. 5-Series 2009 > 2016. 6-Series 2011 > 2018. 7-Series 2008 > 2016. X1 2009 > 2015. X3 2010 > 2017. X6 2008 > 2014. Z4 2009 > 2016. X1 2015 > 2021.