I assume you're looking into replacing the LOW beam headlight so my response is to that.
If your car came equipped with HID's the the correct replacement bulb is D1S.
If not, the correct bulb size is 9006.
Personally, I wouldnt recommend anything other than the correct bulb size. trying to retrofit a H11 bulb into a 9006 or D1S socket just doesnt make sense. I dont think the quality of the actual bulb differs if you choose a different socket (H11, 9006, 9005, 9145 etc) If you purchase a 4300K H11 and a 4300K 9145 from the same company, the quality & output should be the same.
Now, if your housing requires a 9006 bulb, from what I hear you should also get an error eliminator kit.
But I would also recommend a relay harness. That way it draws power directly from teh battery if the stock/factory harness isnt up to par.
Personally, I've purchased HID's from DDMtuning and a couple of Ebay kits and have not had any problems.
I will say tho that I have used a relay harness on every kit tho with the exception of the kit I have for my fog lights. I've been running it this way for about 3 years with no problems.
