Ok Im going to order one but where is it located in the trunk to replace?

 

mine is mounted to the body, just in front of the rack itself. you can pull the carpet down after unfastening and removing the black trim piece at the very back. There are several screws that hold it in place.

 

Just buy 2 small 4 channel amps with high and low pas features one for front speakers and one for rear speakers
I use just one of thesePUNCH Amplifiers - PBR300X4 - Rockford Fosgate® in my X300 to drive 4 6 inch JL coaxial speakers not a bad sound its the size of a packet of cigarettes so being small you should be able to get 2 of them in the original position without to much hassle and at least they are new