To install a 4-Way connector on your 2008 VW City Golf, I recommend the Tekonsha Hardwire Kit # 119178KIT. This harness does include the needed circuit protected tail light converter that will adapt the 3-Wire system on your vehicle to the standard trailer tail light 2-Wire system. This kit also includes a circuit tester that will aid in locating the correct wires to connect to on your City Golf.
I have attached the written installation instructions that you can take a look at. view full answer...