- Hey guys, I have some old Rallye 4000 8" halogens that I want to convert to HID. Does anyone have the links to the best place to buy the conversion kits? Or any experience with doing them? I looked all over Hella's site and could not find anything that was a kit unless I missed it. If these kits work well and are cheap I will do that, if not, I am thinking I may just buy a set of the KC Carbon HIDs. Any info would be great!