I've never put one under the seat of a Contour, but I'm just assuming it would be the best location for wires and stuff... There is a heater duct under there, so that might get in the way. Probly would have to take the seat out to do a good job and hide the wires properly.
You could always mount it under the rear deck and run all the speaker wires under the back seat/carpet/console to get to the HU.
With the Pioneer, it will be in 2ohm mode with 2 4ohm speakers on each channel. So you'll be putting 60W RMS or so to 2 speakers. I dunno if that's work too well.
Even if you used the Pioneer on only 2 speakers (4ohm), it would only be putting 40W RMS to each speaker.
That American Legacy will put about 50W RMS to each speaker.
...but then again, I dunno if you can trust the American Legacy's output power and durability. A friend had a 4 channel from them and the circuitry caught on fire while powering his 5.25" Xplod (crap) door speakers. The plexiglass window let you watch it burn!
