It won't work right if you tried to retrofit a HID kit into your existing headlight. You will blind all traffic.
However, your car did come with HID as an option so you can retrofit a factory HID headlamp complete... for example Bekkers.com have a set but whoa... they are asking $2600 for the kit. The performance is 4 times brighter than european headlight
The second alternative is buy the European headlight kit... for about $1000. This will improve your headlight performance by 3 times when compared to factory headlight.
The third alternative is to replace those yellowed headlight lens with new one... about $160 a pair. Install Plus 50 or Plus 30 headlight bulb for marginal improvement.
If you are handy with used parts... you could try to score a used set of Mercedes HID headlight for your car.
Last alternative is have someone install projector HID lens into your existing headlamt and that will bring it up to HID level. This probably will cost about $900 to do it... Make sure your headlight lens is perfect.