Hello, I have just purchased a Xenon Angel Eye headlight for my SLK R170. I know how to set them up, except one little detail: Where do I need to place the little purple tube, for the vacuum controlled adjustment? Or these don't have this feature? If you need pictures, just ask, though as far as I have seen, they are standard Angel Eye headlights, found on eBay. P.S. The back of it is the same as in this picture: http://www.benzworld.org/forums/attachments/r170-slk-class/200319d1224249377-install-projector-halo-angel-eye-headlights-lp-mbslk98-yd.jpg Thanks!