I got the 6.5" speakers in the rear doors. Didn't have to use the fabricated adapters. We had a set of Pioneer 4 ohm that fit right in the slots. Hubby decided that the amp we have has too much wattage for those speakers, so we'll get a smaller one. Right now, I at least have more sound from the rear. One of the club members mentioned that most people don't care about the rear speakers and work to make all the noise in the front with the big subwoofers in the back. I like the "surround" sound and stereo separation. I would like a little more bass and volume, but that is another addition later.