Audio Systems: Toyota Matrix Audio Input, input device system, rca cables


Question
Hi Scott,
Recently my car's in dash audio system is stolen. Now I have decided not to purchase any in dash audio player, instead, I am planning to use portable MP3 or MP4 or XM satelite Radio or Portable DVD or any other portable audio player to use as my audio player.
My Car: Toyota Matrix 2WD, Automatic, Year 2005, wiring harness,
Can I connect those audio device directly to my car speaker?
Can I install audio input device system directly to my speaker?
Does my car have installed amplifier for the speaker?
Do I have to connect audio input system in the available speaker harnesses that are available?
or Any other suggestion that would help me to install portable audio input devices to my car speakers and less expensive way.

Answer
For an external music source (like what I'm using) you still need some kind of amplifier. The best is what the car came with, a stereo.

Then all you need for the portable connection is this - http://www.crutchfield.com/S-9oDEWuNVIo6/cgi-bin/prodview.asp?i=142FMMOD01

It's not wireless so there's no interference.
Basically it adds an AUX input to ANY radio.

It feeds your audio signal from a headphone jack of an MP3 player( or RCA cables of DVD player) by FM modulation, directly into the antenna input on your radio bypassing the antenna when on, allowing the radio to work as normal when off. It comes with an On/Off switch.