2010 Touareg TDI and P3 Controller

I just purchased a 2014 25FB and am planning to use the Tenkonsha P3 brake controller with my 2010 Touareg TDI. I've seen various posts here and elsewhere about the VW parts that are needed to complete this installation but there seems to be differences between what they suggest. I have the factory install with the 7 blade connector.



I would appreciate any information the VW parts I need, as well as any installation tips or guides.



Thanks