Contemplating replacing all of the speakers in 90 vert with Bose 801/901 drivers (4"). These drivers have 8 ohm impedence. My thoughts were wiring front dash and door speakers together in parallel left side and right side, thereby achieving 4 ohm load. These speakers would be driven off the front channel (no, I couldn't change output levels of the dash and door separately). Then for the headrest speakers, wire in parallel one left and one right channel into each headrest and drive them off the rear channel.

I was just wondering if anyone has any thoughts on this setup.