Here you go:
Unfortunately if you want more bass you need to upgrade the sub, the enclosure and the amp. This enclosure is custom made to fit the 8L A3, built from 18mm MDF and housing the superb JL Audio 6W3v3 6.5" sub and powered by an Alpine V12 T505 300wrms amp hidden behind the rear seat panel.
PM me for pricing if you are interested.