Will an OEM HID unit from MB plug and play on an OEM Standard MB system? It appears that the ballasts, bulbs, etc are incorportated into the OEM HID unit. Will the current wireing harness fit? and will the existing wiring harness take the voltage necessary to fire the HIDs? I am looking a converting the original headlamps on a 1997 E 300D to HID. Later model HID units produced by MB seem to be self contained with their componets rather then like the aftermarket kits.