Hello, the factory steering wheel controls will work after installed our unit.
Could you please send us the photo of your car's dashboard? And could you please tell us the model and year of your car?
Then we can help you to check it?
By the way, this car model is special and has two different radio sizes.
For the two radio sizes, they should install different units.
Could you please tell us your original car's radio size?The below pictures are the measurements for your reference.
If your original car radio's size is same as the first radio size, then this unit will fit your car, please order it directly from our website:
http://www.seicane.com/seicane-s127508-quad-core-pure-android-4-4-4-autoradio-dvd-gps-head-unit-for-2004-2011-mercedes-benz-clk-class-w209-clk270-clk320-clk350-clk500-clk550-with-radio-rds-bluetooth-3g-wifi-mirror-link-obd2-16g-flash-s127508
If your original car radio's size is same as the second radio size, then this unit will fit your car, please order it directly from our website:
http://www.seicane.com/android-4-4-4-gps-navigation-system-for-2006-2011-mercedes-benz-clk-w209-with-radio-dvd-player-touch-screen-bluetooth-wifi-tv-ipod-hd-1080p-video-backup-camera-steering-wheel-control-usb-sd-s018812
Best regards
By
Seicane