I didn't get any photos of the install as I dropped it off before work and picked it up later on. Here's how it sits under the passenger seat with the seat way forward. Normally you can't see it at all. I just need to find some way of stopping it from moving about (not that it moves much).
It also has a small dial to increase/decrease the bass which I've attached to the centre console near the shifter so it's easy to tune for different music.
I'm happy with how it sounds for the most part. Some music sounds brilliant, even when up loud. Some stuff is a bit too heavy on the bass (more noise than bass), although tuning it down a bit helps it's not perfect. Some of this is due to noise from the door trim so I'll fix this first and see if that helps.
I'm wondering if there's some equaliser in the OEM head unit that is set for standard speakers with no sub. That's sort of what it sounds like. Unfortunately I don't know enough about car audio to know what to change and it seems like the more I read, the more confused I get.