The F30 belongs to my mate. I'll get some more pics next time of the F30. It's beautiful in Estoril blue.
We opened the OEM sub enclosure in order to fit the XL woofers in there as the cone is about twice the depth of the enclosure. We cut away the bottom and then sealed it back in place around the floor so it's still a ported unit in the same way as stock. We silliconed the mounting blocks (12mm MDF) into it as well and mounted the driver there.
The stock grille went back in place with about 1mm to spare! We were thinking we might need to space the stock grille back up slightly. And similarly from the bottom of the magnet to the sound deadening on the floor of the car was less than 2mm I guess :-) It was close!!! But it worked well.
Previously: 2003 Peugeot 206 1.6 8v | 2006 E90 320d M-Sport, 19" BBS CH, Full Ice-cold JL audio install, August 2010 Total BMW 6 page feature car. | 2003 Nissan 350Z GT Coupe 286BHP
Now:2010 E92 LCI 335d M-Sport