I am looking to add an aftermarket GPS navigation system to my 2001 C240 (US). Any thoughts on which is better between the Alpine IVA-W205/ PMD-B200 or the Pioneer AVIC-Z2? I would like to keep my steering wheel control and 6 cd changer if possible but am willing to give up the cd changer. I have a Power Acoustik PAVN-4210 enroute but I don't think it's compatible with my stock system, does anyone know if it is?