Does the 211 have projector style headlights when not fitted with xenons from the factory?
If so you could put an HID in there, but not 6000k, far too blue, 4300k is oem looking and gives you the best illumination, no one would ever know it was not factory xenons.
Just make sure you get them aligned properly once installed so you don't dazzle people. And make sure you use the height adjuster if you load the boot up too.
I put Nightbreakers in my ML, and it improved things slightly but after 10 years with cars with xenons I had to put some HIDs in and moved the Nightbreakers to the main beams.
I took my car to an MOT centre and gave the guy a tenner to allow me to align them properly using their chart.
If you don't have projector headlights though forget it, even using the H7R HID kit for non projector headlights, you will still dazzle others.