As far as I'm aware there are HID kits out there that are real but only the guts like the bulbs and ballasts, you've got to remember the light housing which is set up for regular halogen bulbs might not be suitable for HIDs, there are reflector and projector housings and respective bulbs. For cars that have them as a factory option you'll usually notice they are projector and have 3 things in common, automatic light levelling, headlight washers and that the washers are heated. If you are thinking of getting them, go for German made with 4300k colour.