I replaced the factory amp with a Kenwood eXelon x801.5 amp using factory wiring/connectors. (minus the power/ground and a seperate out to the rear sub).
It sounded pretty good. That said, I recently installed an Android based replacement headunit in the navigation cubby... this comes with a 32 band eq and has it's on speaker level outputs thats now feeding the amp... the setup has never sounded better.
https://photos.app.goo.gl/gfwRpGp3PGe21QwWA