I've just let my T6 go, sad day but before it left I removed my Kenwood KSC-PSW8 underseat subwoofer, suitable forT6 models with 2 x front seats, but can't see any reason why it wouldn't fit under the double passenger seat either. Includes head unit adapter to avoid any cutting of wires. Purchased from Vanstyle at the beginning of last year, paid £300 for the kit, all the technical info is on their website. I do have an MDF carpeted underseat mount if wanted, can throw that in - £175.00 collection from PE21 or can be put on carrier for £10 if required