and here's what's I've come up with for an enclosure/amp rack
to situate like so: (sub and amp positon can gladly be reversed)
as a general idea, I just want something simple and unobtrusive, the sub enclosure portion will be walled off so it'll be about 12" wide and 14" tall (ish) and the amp will have about 24-26 inches so I'll just build it into the recessed area next to the sub. anyway, my conundrum is wether to face the sub and amp towards the tail lights or toward the front of the car?
i'd like to face them towards the front of the car for the stealth install, but I don't want to muddy the bass or heat the amp up any extra...
and I just want it to be all around musical, with tight punchy bass (no rap all she listens to is vocal music and pop) and I don't want the response to suffer because the woofer is firing into the seat.
A friend of mine did his sub in the spare tire well and built his amprack onto the back of the seats. It actually looked nice and clean, and when you needed to, you can just cover the sub with a piece of plywood and sit stuff on top of it.
IMHO opinion I would fiberglass a sub box into the spare tire well and recess the amp into it as well. I plan on having that car someday and that is my plan. Kinda like this:
that was an option, but as much as she gets groceries and puts liquids and stuff in the trunk, I didn't want to chance some sh*t I paid for getting ruined and getting the pouty "I'm sorry honey" face
(the back of my hand is itching just thinking about it)
hatchbacks like the scion tc tend to be pretty forgiving as far as sub placement, but that doesn't mean one location can't potentially be better than another for your specific application. it could be facing towards the rear of the vehicle, or corner loaded, or facing up towards the glass, etc.
if you really want to pinpoint it the best method would be to build a good solid temporary enclosure that you can move around and do a lot of listening tests. then you can build your custom enclosure and amp rack taking your listening results into consideration along with the aesthetic side of things.
Play with it like jed says, but shooting it facing backwards (towards rear) will make the lows bounce off the back glass and will reflect nice and loud towards the driver.