I've ordered my 2.5 Sport with only the subwoofer and backup camera installed, hoping to find a high-quality double-din navigating audio system. Every single one I read about seems to have some deficiency (I can't find any with completely excellent reviews). Anyone familiar with the best of the best new systems? I'd prefer Tom Tom for the gps, but it seems only Sony is offering that, but I might have missed something. I'd prefer a real volume knob so I don't have to push buttons on the screen to turn up/down the volume.