some of my problems:
1) failed HID lights. Had to replace the whole thing. Forgot which side
2) failed 2 front suspension. Dealer said the pump won't pump the thing up and thus its a frontal replace! $$$
3) total lost of the cluster. Can only replace
4) keyless-go not working
5) steering rod noise turns out to be steering rod wear. $$$ too.
in general, good car but nothing compared to W140. BTW, I rarely drive the W220, I drive the 140 much more often.