Here is my Kenwood eXcelon KDC-X492 head unit connected to my Creative Zen Vision:M Mp3 Player via 3.5mm male-male cable.
The Mp3 player is attached to the dashboard with velcro.
In the compartment underneath the head unit is the most useless invention ever, remote controls for car stereos. haha
Here's an extension cord which has 3 standard 120 volt AC outlets on it so I can plug in my laptop or anything else under 400 watts.
Here is my trunk...
You're looking at 3 Rockford Fosgate Punch P325.2 amplifiers. Each amplifier has 2 channels and pumps 80 watts through each of these channels.
These amps are connected to 6 Polk/Momo MMC650 Speakers. I didn't post any pictures of the speakers on the final page becasue they are covered by the car's factory grills.
On the side of the amp rack you are looking at a Cobra 400 watt RMS power inverter to give me AC outlets.
Here is a terrible quality picture of a decibel meter measuring the volume of my system. It's a cheap $50 decibel meter, but it is accurate to within +/- 2 dB.
On the screen you can see the system pumping 108 dB. It gets to 105 perfectly without any distortion and starts to distort thereafter.
At 108 dB there is some minor distortion. The system is capable of 115 dB without blowing anything, but there is some serious distortion at that volume.
Who needs that much sound anyway?
For those of you who are unfamiliar with decibels, here is a web page with comparions to other devices:
http://www.gcaudio.com/resources/howtos/loudness.html.