It will fit, but you might need something to keep the bulb steady.
go here: http://www.2phast.com/190E/default.htm
click on the "euro headlight/HID install
there are easy step by step instructions on how to install HID's.
Its a piece of cake!
1987 mercedes 300E
1995 e320 conversion(hated the 300e grill)
Monochromatic Paint (Custom Blue)
Flat Badged (front)
custom "carbon fiber" console
18 inch HP EVO rims
Sold! Now I drive a Monte Carlo SS