You should contact Hella USA (the manufacturer) for more information regarding the installation process. Hella might be able to send you the installation procedure, so you can digest it and decide if you have the skills to do the job. The most complex part is the Headlight Washing System if you don't already have it.
I can tell you that the HID does improve the side vision as well as the distance vision. With HID, I don't even need to turn on the fog lights in rainy days. I agree with Larry that the HID does not have the high beam capability, but how often do you use it?
99 E430 Sport