I have a 2013 Passat TDI SE Roof Nav with the RNS315 headunit.
Kit was from Bold Sport and I followed many of the tutorials and grabbed what I thought were the best of all the writeups.
Basically the process is as follows...
1. Take license plate off - not sure if this is absolutely necessary but I did
2. Remove the trunk upper liner cover - remove the 2 torx screws in the pull down recesses and yank like hell - half of my clips stayed in the trunk and had to be yanked out with pliers and slid back into the holders in the liner cover.
3. Remove the 2 X 10mm bolts that hold the trunk handle plate in place and pull the plate out of the way, you can leave the plug in place for now.
4. The Handle will come out from inside the trunk to the exterior if that makes sense, the new handle goes in from the outside of the vehicle.
5. Remove the wire harness from the handle and plug it into the new handle. Push the new handle back into its opening and replace the plate and 10mm nuts.
6. I made the 3 electrical connections necessary in the trunk. The power, reverse light trigger and ground. The more complex connection was the power which I connected to the trunk light on the passenger side wall towards the rear of the car. I made the ground connection to the passenger side tail light plug with a tap and I made the reverse light trigger connection to the drivers side tail light plug with a tap. I should mention that the power connection was soldered, taped and shrunk wrapped - highly recommended to use an Add A Fuse here.
7. You need to remove the trunk hinge cover on whatever side you want to work on. I chose the passenger side since feedback was that it was less crowded to run all the wires. You need to run the power wire and the video cable up whatever trunk hinge you decide. You can see there is a channel molded into the cover where the wires run so there is not a lot of room.
8. Now it is time to work at the front of the passenger compartment. Remove the trim surrounding the radio.
9. Remove the radio 4 X torx 20 nuts (might be larger but 20 worked for me)
10. Plug the video cable into the back of the radio - it is obvious where it goes.
11. I removed the side dash cover on the passenger side and with the radio out you can see where the video cable needs to go...I used a coat hanger to help or any official fish tape will do.
12. Now basically you just fish the cable down the kick panel, under the door sills, and up along the rear wheel well (from the inside). You dont need to necessarily remove all the trim pieces - just enough to work the cable through. Use patience and it is not that bad.
13. Run the video cable along the power wire from the trunk light up the hinge. Now the troubling grommet. So what I did was pop out the grommet and with a razor blade slice from the outside to the center of it and placed the video cable and power wire there and popped the grommet back in.
14. Replace the hinge cover ensuring the wires are all in the channel
15. Now - before the rest of the trim is put back and the radio fully re-installed it is time to break out VAGCOM.
Open VCDS, Select control module
Click on Coding-07
Click Long Coding Helper
click on byte 3 (it is the 4th window from left....color will change from green to yellow)
checkmark Bit 6 (Rear-View-Camera(RVC) installed/active)
click exit to get back to prior window
Click Do It!
Coding Accepted, click OK
16. Fire up the car and put 'er in reverse for some rear view camera goodness! If everything works put all your trim and stuff back on permanently.
Reverse light trigger wire
Trunk hinge passenger side
A special shout out to mpistone from the other board
as I borrowed most heavily from his post.
A last thought - it is not wise to take on such a project without a multimeter. There has been mention of the proper color of wires for power, trigger etc..although one universal thing - to Germans Brown is ALWAYS ground. One last quick check for power with a multimeter can save a lot of headaches.
All in all not too bad - took just a little under 2 hours from start to cleanup.
Oh yeah...one final final thought...dont forget to take the protective cap off the camera lens...