Check out these videos on installing a trailer hitch.

Hitch installation:
https://www.youtube.com/watch?v=zEraR5BJ4BM

Trailer light installation:
https://www.youtube.com/watch?v=T3fLMwNfE4U

I used them when I had an Audi Avant and needed a trailer hitch to tow, my jet boat and jet ski. Never had any problems with the hitch and wiring that I brought from them.

I was lucky (?) when I brought my X5. A factory hitch was already installed and the wiring was also included.

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2006 Infiniti G35
2001 BMW 3.0I E53 X5 Build date 08/2000 SOLD
Lotus Europa 1970 Destroyed by fire
Lotus Europa 1970 S2 Renault Powered
Lotus Type 52 1970 Twincam Webers Powered
PORSCHE 911 Targa 1982 The Garage Queen
Audi Avant donated to Kars for Kids
BMW 525IT Sold
Audi 4000CS Quattro Sold
Jensen Healey Lotus Powered Sold
Opel 1900 Sold
Triumph Spitfire 1971 Sold
Triumph Spitfire 1968 Sold
Plymouth "Cuda" 340 Six pack SOLD