thats my alpine CDA-7894 head unit installed.
i also have alpine component speakers (Type-S SPS171A) up front, diamond audio 4" speakers in the rear, an alpine amp to power em all (MRV-F340), and now i just got an infinity basslink powered 10" sub.
my amp was placed behind the rear seats:
some poeple prefer to put the amp in the close-able pocket in the trunk, but i prefered to use that space for storing tools and other doo-dads.
a lot of people put changers in the armrest upfront, but if yours doesnt fit then im sure itd squeeze in under the seats.
check out my site for more info and some more pics.