You usually have to make do with beschraenkter energy supply (12 volt electrical system) must usually be small as possible and are exposed to large loads during operation, both thermally and mechanically.
A solid structure is therefore a prerequisite for a well-functioning car audio system.
For the hobbyists, it is an interesting series of schematics for the DIY around the car audio section.
Here is a small selection of them.
Here you will find Schematic Circuit Diagram for DIY and further information on Car Audio HIFI
|Adapter for portable CD / MP3 Player||www.aaroncake.net/circuits/cdsupply.asp|