Hi, I'm installing an Panasonic CQ-DFX608 CD reciever for my 94' Taurus LX. I have the stock premium sound system, I dont know if it's JBL or not since it did not have a subwoofer. I was snooping around today, and I found that there is a silver/aluminum object that looks like an amplifier in the trunk. I dont know if it is to power the speakers or what, but the two rear speakers is connected to it. But since the aftermarket CD reciever is rated at 50W X 4, do I need to throw the stock silver/aluminum amplier away so the speakers can take advantage from the 50W x 4 power of the CD reciever ?