subwoofer

Does anyone have any experience running these Focal ISUB Twin subwoofers in a Gen3? Focal appears to have kits for a Gen2 but my local stereo shop says their Focal rep says they would also fit in a Gen3. I specifically am looking at options for behind the seat so I am a bit skeptical on fit...

Thoughts? Use the 2 small batteries under seat to power amp and under seat subwoofer box. Pull signal from 2 wires that plug into oem sub. If this could be done you could keep all the wiring under the seat and not have to punch up thru the firewall.