It is probably a bad thing that you are asking this question and if you have any friends who have done car systems before i would ask for their help.
its pretty simple though. run the power, status, and ground then hook up the speakers to the correct polarity.
Im going to have to sadly disappoint you and tell you that the cadillac still will not beat the SRT 8. In a stock to stock match, the SRT beats the CTS by almost 2 seconds (10.75 to 12.3) and that is assuming you are talking about the cts v2. sorry . . . . .