So I got the Kicker Hideaway HS10 sub fitted this morning and I'm pleased to say I'm very happy with it. Now at last I can say I've got the sound I want. It's fitted on the floor under the passenger seat but it definitely sticks out into the footwell. I'm ok with that for several reasons: firstly, I want some air around it and don't want it getting hot, especially with these summers we've been having. Secondly, it's got quite a lot of controls that are accessible on the side of the unit and I can still reach these. Lastly, it's built like a tank so if it gets the occasional knock from back seat passengers it's no biggie (it's screwed into the carpet with the supplied bracket.) It has a remote control knob mounted on the centre console where I can dial up and down the amount of bass. Soundwise, it really fills out the bottom end of my favorite music, old rock (The Clash, David Bowie) sounds punchy and great, newer dance stuff like Daftpunk sounds awesome. It doesn't shake the whole car, which is fine with me as I'm not really a "bass head" and I don't listen to a lot of Techno etc. Even old sixties stuff and jazz has a lot more presence and impact. It cost me £480 including fitting and it was certainly worth it, it's taken the sound system in car up to where I wanted it. All in I've spent about £1400, not cheap by any means but a good sound system is important to me and with Amazon music HD downloads on my phone I've got all the music I want so all in all I'm pretty happy. Not sure if something like the Phoenix 10 inch discussed wouldn't be as good: it looks very similar to me with virtually identical specs and build and it's nearly £200 cheaper but apparently the Kicker is the best of its type.