On inspection the A3 modification listed above simply tells the "09-Electronics Module" that "Coming Home lights is switched on" - this is what the additional repair wire connected to ground is doing. Of course you have to code this module to tell it it has the "Coming Home function". What it does not do is use this function in the dark - it's day and night functionality as there seems to be no light sensor - as stated in the instructions no light sensor rear view mirror required.
This may work on an A4/B6 by adding a repair wire to ground to connection "T32b/24" on the "09-Electronics Module". What is not clear on the A4/B6 is if a light sensor is required for this full function to work. For reference the Photo Diode light sensor in the RVM is connected as follows: T32b/30 --|>|-- T32b/18. Note you will have to recode the "09-Electronic Module" for coming home lights and maybe the light sensor, etc. - info is on the Ross-Tech website.
I would try this out and test but I only have an "8E0 907 279 B" module and would require a "8E0 907 279 F" module.
If anybody has a spare compatible unit, send it to me and I will try it out.
Otherwise perhaps someone else could try it?