How can you make the amp come on with aftermarket headunit
 

Ok so i know its been said many times that you can make the factory amp come on with an after market HU but thier has to be a way I mean what turns it on thier has to be some kind of 12 volt signal that turns it out just like any other amp so why couldnt you Tap into it and turn it on and put RCA converters on the Factory inputs and run RCAS from youR HU to the amp and some kind of remote tun on and thier you have it back to normal. I know this all sounds good in theory but i dot know how to make it work here are the pinouts for my amp if anybody has anyidea on what wires i could try that would trun it on let me know

2000 DSP Premium Sound connector information

The pinouts for the 15 pin connector are:
PIN - CONNECTION
1- Sub 1 +
2- Sub 2 +
3- LH Rear loudspeaker + (Touring LH rear speaker ground)
4- Radio on/antenna signal
5- RH rear loudspeaker + (Touring RH rear +)
6- Sub 4 -
7- Sub 3 -
8- Terminal 30 connects to Fuse 56
9- Sub 1 -
10- Sub 2 -
11- Touring LH rear +
12- Touring RH rear -
13- Sub 4 +
14- Sub 3 +
15- Terminal 31 connects to Ground Point

The pinouts for the 18 pin connector are:
PIN - CONNECTION
1- Not used
2- Low freq. negative (-) signal - Transceiver/charging electronics
3- Not used
4- Not used
5- I-bus Signal Line - Splice X18344
6- Not used
7- Not used
8- RH front speaker - Connects to Radio
9- LH front speaker - Connects to Radio
10-Not used
11 Low freq. voltage (+) signal - Transceiver/charging electronics
12-Not used
13-Telephone mute signal - Transceiver/charging electronics
14-Not used
15-Telephone ON signal - Transceiver/charging electronics
16-Not used
17-RH front speaker + - Connects to Radio
18-LH front speaker + - Connects to Radio

The pinouts for the 26 pin connector are:
PIN - CONNECTION
1- LH front woofer +
2- LH front woofer -
3- Not used
4- RH front mid-range -
5- LH front mid-range +
6- Not used
7- Not used
8- Not used
9- RH front mid-range +
10-LH front mid-range -
11-Right rear mid-range speaker/tweeter +
12-RH front tweeter +
13-RH front woofer +
14-LH front tweeter +
15 LH front tweeter -
16-Left rear mid-range speaker/tweeter -
17-Not used
18-Not used
19-Left rear mid-range speaker/tweeter +
20-Not used
21-Not used
22-Not used
23-Not used
24-Right rear mid-range speaker/tweeter -
25-RH front tweeter -
26 RH front woofer -

could it be #4?

This will not work (or at least, it is not worth the effort). The DSP amplifier is a very high-end, complex design and integrates through computer communications with multiple components in the car (MID, radio, phone, etc.). The amp is totally different from any aftermarket radio architecture. When the BMW radio detects a DSP amplifier, it completely changes its behavior. The radio actually becomes a "dumb" device and sends a two-channel, full volume line level signal to the DSP amp. The DSP amp is the thing that does all of the volume, balance, fader, equalization, etc. changes. These are a few of the major barriers that you would encounter.

• The DSP amp requires balanced audio inputs
• The DSP amp expects full-signal, line level inputs (with no volume, balance, fader, etc. modifications)
• The DSP amp must communicate with the head unit controlling it through the I-Bus

Oh Ok, Thank you very much for your quick response