thanks,for replying ,, some people told me that i need a 5 channel amp, every door has 2 speakers ,one big and one smaller at top ,plus on the dash left and right i have 2 small speakers,and also the sub in the trunk,all bmw oem. but not to worry ,because after few days ,i manage to make it work to get my sound and keep all oem original stuff.,just had to work around at the amp wires. thank you for all your help!