I'm really not going to go over the steps on how to install new HID bulbs in a B8.5 S4 as there is many Youtube videos out there to cover that. I will let you know that you will need to remove the Air intake box on the passenger side, so plan a head on that. I will warn you these are 4200k color so they are white with a hint of yellow. For those of you that want the pure white, well these aren't going to be your bulb. I like them because simply because this color works better for all weather situation. 5500K and higher bulbs have a hard time illuminating wet roads like what we experience in the Pacific Northwest, so the 4200k is the ideal color.
In summary way brighter, and I'm happy I got them. Sorry pictures won't do justice so you will just have to take my word for it.
I used the projected fog lamps that came stock off a MK3 Jetta GLX VR6. No, not my old car, but my little brother's car as he was donating it. His car had seen better days so I took what I needed before it was towed away.
Eye'ing the MK3 fogs and a spare set of stock B5 S4 fogs I had, there looked to be some possibility to making it work. Obviously I'm looking for simple functionality because the 3000k HID's I have in my stock fogs now just weren't being used to their full potential.
Installed a DDM 55 Watt 4500K Slim Ballast HID Kit to replace the OEM 35 watt HID system. It took me about 2.5 hours. The hardest thing was getting the OEM ballast out. They have very weird Hex screws... likely some security feature or something. The 55 watt HID kit aren't as bright as I wished they would be but they are still brighter. This kit provides more of true white color rather then a faded blue like my old OEM HID bulbs.
Also got a set of 3000k H7 type bulbs from DDM Tuning which I will install in the fogs. My plan was to us the old OEM Ballast, but that plan was going to require too much wiring for my liking. So when funds are available I will get another set of DDM slim ballast HID kit, but it will be the 35watt instead of the current 55 watt.
Finished installing Lamin-x Covers on my fog lights. I went with the gun-smoke tint which makes the fog light fade in with the surrounding lower bumper grill. No changes in light output that I can notice.
Well I have discovered that I have two cracked rims. The front driver side rim and the the full sized spare rim. I went to Achtuning and got a new rim for $200. As for right now I will just have to run around with no spare until I can get another rim.