I purchased all set of the B&W speakers and replace all of them except the rear doors cause they don't have mid and tweeters . I will love to add original subwoofer but dont know here I can install it . I removed back rear trunk carpet but I dont see where can be installed ? Please help .. Also can I swithc amp to B&W I know it uses more wires but is it save to plug in ??

Thank you in advance