2000 BWM 540 Sat. Radio HELP!

I am trying to install a fm modulated satalite radio system in a 2000 BMW 540i.  This is the car that has the multi antena system to improve reception at all times, the problem is how do i get my modulated signal into the system, i found one antena next to the amp and changer on the drivers side in the trunk, but disconnecingthis makes no difference the car picks radio station fine, and running the satalite radio through there produces a less than diserable sound, if anyone has some pointers and advice on this car i would greatly appreciate it   thanks  

I think that's all the modulator is looking for is an antenna type of signal. Just get an antenna adapter and run it from the antenna that plugs in to the back of the stock deck and then there should be another antenna that comes out of the modulator itself and you run that back into your head unit. (You'll need an adapter so that the male matches the female on the HU itself).Andrew Weitzel

MECP First Class Installer