DISCLAIMER:   The install of lights into the air ducts of the Turbo (1.8T or TDI) Jetta is not recommended. Making these modifications is at your own risk. I make no claim that these modifications will keep you from having problems with your engine, nor am I aware whether or not these modifications will void your warranty. Please don't email me or stalk me because you screwed up your car or voided the warranty - I already told you that this is not recommended. Once again - Following these guidlines is at your own risk.

Parts Needed:
Hella Micro DE Foglight Kit for Jetta, I ordered the lights from amimotorsports.com for $265, There are other places that sell this kit, like parts4vws.com for $250 (you must do a search and specify the VR6 engine, under lighting) or you can get into a group buy over in Vortex.
EuroSwitch, for $85 at parts4vws.com
VW Wiring Repair Kit, Part# 000979126 from your local VW dealer for $2.
TT Wheel Wheel Vent, Part# 8N0821172B from parts4vws.com for $30.
Fog Light Wiring Kit, from Advance Auto Parts (or any auto parts store) for about $20.
Black Trim Paint, special paint for plastic, from any auto parts store, about $8.
Flexible Wire Conduit, available at any auto parts store for about $5.

A few points before you start:
1) The plastic for the replacement ducts is hard resin, not the soft plastic that the VW comes with, that's why I decided to go this route.
2) I messed up on one of the holes, the middle hole that I cut out on the left side should stay in there. I cut it out and then realized that the light housing support bracket crosses over that space. (I painted the bracket black and you can't tell that it's there unless you crawl under my car with a flashlight. The bracket blocks about two/thirds of the hole, so you might as well not cut it out)
3) I added the Audi TT well-wheel vent to give my car additional airflow to the intercooler. I highly suggest that you add that also. John's page has a good description on this vent install.
4) I used the Euroswitch instead of the included wireless remote that probably added $100 to the cost of the lights. (I sold the wireless relay and remote to a buddy for $40) You can always use the wireless remote and save some trouble and money, but I wanted my lights to be as stock as possible.
5) Feel free to make whatever changes you deem necessary. Example - you may want to color match the ducts to the car.
6) These instructions are written with the assumption that you are going to use the Hella Jetta Foglight Kit. They also assume that you have a decent knowledge of automotive wiring and a modicum of common sense, in other words - Think about each action before doing it.

All in all, it took my about 6 hours over two weeks to do this job right. (In my spare time)

First – Prepare the duct:
Take your time cutting the material – I used a Rotozip tool to rough it, then used strips of Sandpaper to stroke thru the slots to give it a real smooth finish before painting. (Paint the center duct, so it matches, and the old ducts too, in case you ever return it to specs)
I made quite a few mistakes – but don’t worry, at the angle these things go in at – nobody will ever notice. Heres a Before and After shot of the duct.

Second – Prepare everything else:
Once you have the vents ready and painted, make sure you have everything else ready before you start the install part. Do Not install the lights into the ducts yet – that is the last thing you do.

The actual install took about 4 hours. I removed the airbox and ran all my wires down to the horns. I used the supplied Hella wires except, I cut off the harness plug that plugs into the wireless relay and replaced it with the plug that came with an aftermarket relay. (I bought an $18 "Foglight Wiring Kit" at Advance Auto Parts, throw away the little switch that comes with it – you use the Euroswitch instead)) You have to combine the positive wires (the horror) because the aftermarket relay only had one output. Hopefully, you know how to wire a relay from there. I ran the wires to the battery thru the conduit or the "plastic wire hose" to the battery terminals.

The trigger wire was a pain - do it first. Follow these directions I stole from John's Page

Stolen Instructions section:

The only wire left had fairly explicit directions.

After removing the wipers and the black plastic tray at the base of the windshield, the main wiring harness is visable. My father put a small slice in it the rubber boot, and threaded a car antenna through the firewall. On the other side, we taped a piece of speaker wire to the end of the antenna, and then pulled it back through. We then taped the wire from the relay (the one that had been labeled) to the speaker wire, and pulled it back through the firewall.

The label said it went to spot 8 on the euroswitch plug. Notice that the wire has the correct end and rubber grommet on it. Go Potterman!

The euroswitch install is basically like the regular switch removal. Prior to install, I put it to the 'off' position, and then pressed the knob inward, and turned it clockwise. This retracts the tabs that hold it in place. Here's my switch installed.
The only thing left to do is clean up the wiring, and mount the relay. My father fabricated a quick relay mount, that used one of the existing bolts. We used a pop-rivet to hold the relay to the bracket. You can also see the gray wire going to the euroswitch; we followed the hood release cable to get to the back of the hood so it could go through the firewall.

End Stolen Instructions section

Differences From John's Install: I did not have to take the window washer grill off, I did the whole thing thru the slots. (The brown wire is my trigger wire.) Since I didn't receive a "Ready to go" kit, Use VW wiring repair kit Part#000979126 to plug into the light switch harness. Order this now, because my VW dealer didn’t keep them on hand. To disable the DRL's - Remove and tape wire #3 (see note at bottom of page)

Pull off the cover to the wire conduit and run the wire thru that then up to the relay (you must remove the weatherstripping that runs along the hoodline, pulls right up) I screwed the relay in the same place that the shitty Hella manual says to put the wireless relay. You do not have to worry about messing with any of the factory relays with my install - only the switch.

BTW, John's install gives you foglights without doing all my mods and for a little less money. You may want to consider it. I just didn't like the idea of messing with my factory lights. I could live if my fog lights stopped working due to wear/time or poor install, but if the main lights went kaput - that would be a major problem.

Wiring is done:
Install the ducts, follow the shitty Hella directions. When drilling the holes for the ducts – push them in as far as you can when marking the spots to drill.

You may have to cut some plastic away to get the clips to work right – no biggy.

Don’t forget to bend the horns out of the way and cut that plastic do-hicky off. On my car – there wasn’t anything attached to it – but the directions show some sort of sensor and include a bracket to mount it elsewhere. (Probably something on the Euro Version cars)

Last: – Install the lights into the ducts and hook it up.

Aiming is a bitch because you have to remove the duct for each subtle adjustment, but do yourself and everyone else a favor and make sure they are aimed properly. It’s even a good idea to let someone else drive the car while you drive in front to see if they blind you or one is off more than another (the wall trick just doesn’t work that well)

I did not have to remove the bumper, but I did drill three holes thru the crossbrace to zip tie the wires to, that cross over to the passenger side light.

Note: - if your good and patient - you can remove the pin from #3 of the Euroswitch (Disabling DRLs), cut the pin wire off and connect it to the trigger wire to plug into #8, saving you the trouble of ordering the wire repair kit.

Final Words:
Use the factory bulbs and never use anything but the same type. The wiring, housings, relay and switch are all designed for 55watt bulbs. Putting 100’s in there is just stupid.
Take your time and do it right – anybody can hurry and do a shitty job. My car has been to the dealer three times and they think the lights came standard, all wires are hidden or run thru conduit.
Here is a finished, installed, close up of the Passenger Side Duct. Here is an Extra Large Version (180K.)

Links I used for info:
Lights Out
Some Guys Page
Johns Page

Good Luck
Rookie