I have a custom-made ‘incognito’ sub enclosure with SB Acoustics 12” subwoofer for E92. The sub enclosure is 1 ft^3 and fits neatly in the left corner of the trunk out of the way. Check out the specs of the sub here:
https://www.madisoundspeakerstore.co...-12-subwoofer/
$250 net to me. Thanks.
Steve in NC