2001 mercedes benz ML 320 factory amp

I'm installing an extra amp to a 2001 mercedes benz ML 320 sport. I need to get to the factory amp so I can get the speaker wires to hook up to the hi-lo, but I can't find it. I was told it was in the trunk area. I took apart both side of the rear panels but there's nothing there except for a cd changer on the passenger side. Can the factory amp be located elsewhere? And also what are the colors to the speakers?, if avalable. Thanks, need info asap.

I'm showing the left side of the trunk.  If you can't find it, test the wires behind the deck.My ex once told me I have a perfect face for radio.

Those amps are usually located in the drivers footwell. Lift up the carpet and there is a storage compartment where the amp is locatated. You will have to unscrew a cover plate to access the amp. Jazzy

thanks fellas :)