I started doing car audio in the early ages of car audio (about 1980) . I have probably installed 300 systems to include some very high end equipment in many exotic and normal cars. I am also a broadcast television engineer who specializes in system design and installation. That being said, and fairly needless to say, I can't leave a stock system in my cars. I even had a system worth (including my installation time) about $5000.00 in my 1986 Isuzu Trooper 4x turbo diesel hunting truck that I only paid $250.00 for the truck!
Anyway, my plans for this car are a 4 or 5ch amp (depending on whether I want rear speakers) and a sub box I will build using a box program specifically for the sub I choose, and where I want to put it. Here at work i can get great deals on Amps and install equipment since we are also dealers for a place called DBL Distributing. I think I will use the Alpine 6x8s up front, and a quality sub and do a 4ch amp since rear speakers never are needed for my tastes in a small car.