This article is from the Car Audio FAQ, by Ian D. Bjorhovde (firstname.lastname@example.org) with numerous contributions by others.
This section describes various components that you can have in a car
audio system, along with common specifications, desirable features,
some of the best and worst brands, and so on.
Be aware that there is no standardized testing mechanism in place for
rating car audio products. As such, manufacturers are open to
exaggerating, "fudging", or just plain lying when it comes to rating
their own products.