I was thinking of getting a slim active sub for my XH. I have a sony head unit (with only 1 RCA out set though) and Rockford 6.5" 3-ways in the doors. I don't want to cut the rear wall to put a big sub and amp in.
I noticed there are a few brands around and was wondering if there was anything that was particularly good or brands worth staying away from. I don't want to be shattering windows but an easy install to help bass would be nice. I was looking at the log subs but I don't think they will fit in my ute so probably go for the flat ones. I found Fusion and Boss ones so far, and some brands I never heard of (Titan, Blitz) on ebay. Any opinions would be great as I have only started looking into this recently.

i'm fairly sure JL do an active slimline, i'd look at that over fusion or boss...
i know XHs don't have much room behind the seats, but maybe a passive tube 10" and get a small d-class amp under the seat?

I doubt you would get a sub behind the seats without modding the firewall, atleast I couldn't in mine anyway.
What I did instead was rip out the bench seat, throw in some buchet seats, then put a 10" pioneer slim sub in between the seats. I did make up a whole custom centre console (with cupholders!! ) for a little bit more practicality and looks.

I can get some photos if you would like to see how it looks.

Haha that sounds cool. I have a manual so no bench seat. Could you put a picture up, I'm interested to see what you did. Cupholders would be nice too. Man they build XHs no space.

I'll have to get a pic tomorrow for you. (Girlfriend nicked my camera)
I know what you mean about having no space, I can barely fit a piece of paper behind my seats, really makes you think outside the box though if you want to do anything.
And the cupholders are the freakin' best thing EVER!!! I really don't know why the XH's didn't get them as standard.

Here's a pic of my setup for you.
Will all be covered in dead cow eventually.

depending on how much you use the full tray, you could make a box with an internal mount sub, waterproof it i.e checkerplate or paint and run a port through your back wall to the cab

I'm trying to avoid cutting stuff up, including the rear wall and my tub liner in the back. The bit between the seats might be the best bet, cause then I can take the box out and not have any holes left. There's a bit of space behind the glovebox too.

That custom setup looks sweet too, though my gearstick might have to take priority over my drinks.

I still think an underseat setup will be best, but thats for the other options given.