Car Sound System Sites
Absolute Car Stereo Net
Alpine: Only the Best go in Exotic cars like Lambo's
Ample Audio
Audiobahn Systems
Audio Discounters
Audio FAQ
Audio FAQ/2
Audiomobile
AudioToy
Audio Warehouse
Battery FAQ
Bazooka Mobile Audio
Blaupunkt USA
BOSS Audio
Cadence Sound-Competition Systems
Car Audio Gateway
Car-Audio FAQ
Car Audio Forum
Car Audio Networks
CDT Audio
Cerwin-Vega
Clarion
Competition Audio
Crossfire Audio
Crunch USA
Crutchfield Electronics
Crystal Mobile Sound
Earthquake Amplifiers Sound
Eclipse Web
EFXcursion Project Vehicle
Fahrenheit: Power Acoustik
Infinity Systems
JBL Car Audio
Jensen
JL Audio
JVC Audio
Richard Kelsch
Kenwood
Kicker
Lanzar
Legacy Audio
Lightning Audio
Linear Power
MB Quart
Memphis Car Audio
Mobile Entertainment
MTX Audio
Orca by Focal America
Orion
Phase Linear
Phoenix Gold
Pioneer Electronics
Polk Audio
Profile Consumer Electronics
Pyle Audio
Pyramid Sound Around
Rockford Fosgate
Santeca
Scosche
Sony
Sound Domain
Stinger Electronics:  Battries,   Capacitors,  Alternators,  Isolators,  Wiring supplies
TnT Audio
Varad
XM Satellite Radio
Xtant

Resources on the Effects of cranked up sound systems! (Above 85 DB)
No Noise Org    Also covers effects of loud noise!
Hearing Damage and Loud Music
Hearnet Education for Rockers
Decibel Trivia
Tinnitus is a warning. Here are some resources
Tinnitus FAQ
Tinnitus Sufferers may benefit from this Herbal Remedy