I mounted my amp on the side of my sub box and took out the pass thru for a closer fit.

 

awesome. I have an alpine type r as well.
I still have not buttoned it up, nor mounted the LC2i.
How did you find tuning it?
I have not yet done so. Have a mono RF amp. I am new to active LOC's, and still trying to figure it out.

 

And that is what I want to add: a sub grill, just to keep it safe.
I dislike whatever the dealership did for detailing, because the trunk carpet has a stickiness/residue to it, but it seems to be enough to keep the box from moving. I bought weather tech cargo containment system, which I used in my previous vehicle (2013 Dodge Chally)