TRAILER PLUG WIRING DIAGRAM DODGE RAM

Adapter 4 Pole to 7 Pole Vehicle End Trailer Connector Tow
It is possible to use a a female 7-way plug on the trailer if you wanted to using part # 30717 and then using an adapter Bargman 7-Way Molded Trailer Wire Connector - Double-Ended part # 50-67-210 to connect the two plugs. As long as you wire the female plug to match the wiring functions of your vehicle side you won't have any issues.
Curt Powered Tail Light Converter with 4-Pole Flat Trailer
We do have what you're looking for to be able to install a 7 way plug on your 2011 VW Tiguan, and the base of all wiring starts with the 4 way connector; I recommend using the Curt Powered Tail Light Converter with 4-Pole Flat Trailer Connector # C59236, which will give you a 4 way trailer connector that you'll need to start.