Ive got a 99 s70 T5 with the sc 901 radio (3 cd in dash) center dash mounted speaker, and 8 other visible speakers, 9 total visible speakers. I hear this is supposed to be a 10 speaker set, I'm assuming the 10th mmay be a subwoofer that's supposed to be in the car somewhere????? Anyway, it has the two little antennae symbols on the readout, but I get somewhat poor receptioon with it. ??? I pulled back the carpet, and made sure the trunk mounted antennae was actually plugged in, and it is. The other antennae I've heard is in the bumper somewhere, if so, where do I look to be sure it's connected? Thanks!! Also, does this unit have a factory amp??