not after the cubby holes as mine already has them... interested top see what you do as i also have some OEM behind the seat woofers and wondered whats the best way to go about wiring them in...?
Most pre 2014 Alpine amps have high level inputs, so they make a good option, I'll be using the wires going to the existing rear speakers into the high level input to provide the amp it's source.
I've read somewhere that the stock "business" CD player has an Antenna+ feed, so will use that for the amp trigger wire, the rest is child's play
I was actually really impressed with the stock speaker setup at the front end of the car! Although my musical tastes probably differ to most (Alternative Rock / Pop Punk / Classic Rock)
I faded out the original rears as the seats are way too close and just muffle any sound they produce.
I personally didn't have an issue with the way the original setup sounds, I just love messing with stuff, and if I think it could sound better, I'll do what I can to help it