My opinion, NO. Just yesterday, I repaired my subwoofers and reinstalled them.
I had run additional wires and cut the wires at the factory amp, to have the doors and subwoofers on separate channels either as front/rear or front/subwoofer from the Kenwood. After reading ALL 30 pages of the best bang for the buck capacitor install, I figured it must sound good for all of those success stories. SO, I reverted to factory wiring with the Kenwood only driving through the front speaker outs to the factory wiring, and reconnect all wires at the amp the factory way. I then installed 330uF capacitors in the doors, and cranked up some ZZ Top through the newly repaired subwoofers. I needed to play with all the audio settings, but I am extremely pleased with the results. I learned a lot in the process, and highly recommend it to everyone. With the Kenwood using speaker outs, it will overdrive the factory amp quite easily, and you could probably blow out speakers. You can set the "Volume Adjustment" from -8 (low) to 0 (normal). I set it to -6 or even -8 and you can turn the volume about all the way up on the Kenwood, and it is very loud, but not overpowering. I even ran my microphone wire up the dome light area. IF you setup the Kenwood wiring to the rear subs separate, you can choose high pass and low pass cut off in the radio, instead of using capacitors, but I didn't like how I couldn't get full volume from the low voltage pre-amp outs compared to speaker out. And you can only use the HP filter with the subwoofer enabled. With the volume up now, it can be very loud and clear, and almost a back massage with the low bass. I may even try the 470uF capacitors, I think the door speakers can get a bit more bass to them and still sound clean.