hello, I will recommend this better unit to you, which is Android 4.4.4, Quad-core CPU and HD 1024*600 multi-touch screen with smooth operation.
http://www.seicane.com/seicane-s127501-oem-2004-2011-mercedes-benz-cls-class-w219-cls350-cls500-cls55-dvd-android-4-4-4-dvd-bluetooth-in-dash-radio-navigation-system-with-mirror-link-obd2-3g-wifi-quad-core-cpu-16g-flash-backup-camera-usb-sd
1. If your car comes without optic fiber amplifier or fiber optic Harmon Kardon sound system, this unit is plug and play and of very simple installation.
2. If your car has optic fiber amplifier located at your car's trunk or fiber optic Harmon Kardon sound system,please select the option " Support 2002-2012 Year Original car's Optical Fiber Amplifier and Harmon Kardon system " when place order, then we will send you one optic fiber decoder. The installation of this optic fiber decoder is quite easy and we can send instructions to you about how to install it. With this optic fiber decoder's installation, your original car's optic fiber Harmon Kardon sound system and all your original car's speakers will still work.
By the way, to check if your car had optical fiber amplifier or not, you may confirm with the dealer where you bought your car. Or could you please give us a picture of the plugs for your original radio so that we can check for you?
Best regards
Durch
Seicane