Well I have an Avic-d3 and I love it but the naviation tracking is a problem. I had it installed for me and the installer told me that Commanders dont have a speed sensor hookup. So therefore the Nav tracking has issues knowing exactly where I am. It jumps around, cant track which side of the highway I am on, and has real location issues in the city. The unit works together with the speed sensor and satelites to share info on location and I only have the GPS working for me. Has anyone had this issue with their aftermarket nav system? Or have a solution?