I´ve just finished my CarPC projekt. Unfortunately

(but not unexpected

), i´ve got a problem. When i´m turning on my CarPC, the speakers makes a loud noice.
I used the ignition lead to turn on en relay, which turn on both the CarPC and the amps...is this the problem?? What if i used a power-lead from the CarPC to turn on my amp´s? If i could, then i´m sure that CarPC get power before the amps...but would that solve my problem??
//Andreas