I'm considering changing out the factory audio system for something fancier. I haven't made any decisions yet; I'm just learning all I can so I know what my options are. The wiring diagram for the factory amplifier has a wire labeled "DG/WT" that runs to the "Body Control Module" and the "Controller Antilock Brake." Is it normal to have the stereo amplifier connected to the antilock brakes? Should I expect to find equivalent connections on aftermarket amplifiers? For those who have replaced their amp, what brand/model did you use? Was it an easy swap? Can you use the existing speaker wires?

The radio has a wire labeled "YL/DG" that goes to a "Data Link Connector." Is this also a standard connection I would find on aftermarket dash units?