Does anyone know if it'd be worth it to use the factory amplifiers on some aftermarket speakers? As you all know, this particular van uses 4 amplifiers, bolted to the magnet of the speakers. I'd use a pair of 6x9's for the rear side-panel and some 5x7 mid's for the front doors. I get good sound now, but a little exrta mid and bottom end would be nice. Any other idea's would be good too. Thanks in advance.