Just thought I would let everyone know that the 06 Scion HU does in fact plug right in......just as glacticgray05 said. I really thinks it looks nice with the volume knob, but the sound is what really impresses. I am blown away by how nice the factory speakers sound. I have previously had vehicles with the factory upgrade system (Bose) and with the scion HU the 4Runner sounds just as good as I remember those sounding. I know it sounds better than the Bose system I had in my Silverado or Pathfinder. Everyone with the base system should do this. Just curious, what do people have the SSP set up for.....the tC, xA, or xB. I thought it sounds the best on xB, but xA seems to play more highs. I cant believe I waited a year to do this.