Update on mine; got it installed this afternoon. I chose to have the amp mounted on the back (instead of under passenger's seat, where I usually mount them) because I want access to amp controls without having to remove the seat. Dinked around with a few of the settings on both the amp and the (factory) radio, and the thing sounds amazing. Very smooth clean bass. I would expect nothing less from JL. Extremely pleased with it. I have the factory radio on "Hear" profile, which tones down the bass output significantly (otherwise it's way too overpowering, even on Bass -5). I forgot what settings I had on the amp itself because I just left it on what I had it setup for my 12", but I may mess with the LPF to let it reach slightly higher frequencies since it's a 10". I do hear some significant rattle at certain frequencies, but I'm almost positive it's the third brake light (same issue in an old car). Will put some foam tape around it to mitigate the issue.
I salvaged the amp from my old
wrecked tC, but the new box/sub, wires, and install came out to $501.74 out the door after tax.
Most significantly, the intrusiveness of the trunk is pretty minimal. You loose a little bit of depth, but keep all the front side stuff. Plus, with a quick detach of the audio wires, you can pull the whole thing out entirely. It may not be the prettiest thing in the world, but it sounds fantastic. I don't know why I would need a stealth box over this....