Out of curiosity, why do you need a '7 pin' connection?


If you want the car to control the trailer brakes (which AFAIK is the only added benefit of 7 over 4 pin)you need a brake controller in the car (in addition to OE factory wiring and modules)





I *really* like the Tekonsha product line. I tow pretty heavy loads with my truck (11k to 14k lb goosenecks) and they are flawless. Edit: by truck, i mean F250 PSD 4x4..not the x5


Some ntoes:
The "bmw branded" under dash brake controller *is* a Tekonsha P2 (or p3?)...problem is that you need to run wiring from the rear up to the dash. Not hard, but it will be time consuming. You can buy pre-made harness and all that, so no splicing. etrailer sells an OEM version:
https://www.etrailer.com/multi-produ...BMW&HHModel=X5
(here 'OEM' is 'just like the BMW OE version... clearly Tekonsha is the OEM for the BMW branded controller, so a Tekonsha controller IS an OEM controller.... )



Tekonsha makes a 'wireless' controller that pairs to a phone. https://www.tekonsha.com/product/909...l-proportional...
I WOULD NOT GET THAT. I dont need my braking relying on an iphone!


Tekonsha makes an RF brake controller.
https://www.tekonsha.com/product/902...l-proportional
This sits at the rear- basically between the cars '7 pin' and the trailers 7 pin.... You then have a 'controller' that sits under the dash, plugs into a cigarette lighter (or hardwire) that acts as just an interface to the brains and controller that is in the back. (I am pretty sure that after you get it all set up, set the vaules for type of braking, sensitivity, etc) you could REMOVE the interface that plugs in up front and the controller itself in the back will control the brakes just fine. In other words, no 'mission critical control fuctions' are being transmitted via RF while it is running. I THINK. Verfy this.


If I didnt want to run wires (personally this doesnt trouble me) Id get the RF and do a bit of a custom install inside the rear wheel well. ie not hang it outside on the hitch.


Finally anything more that 1500 lbs you want a brake controller (at least here in California). BMW is kinda sneaky about towing capacity and when you need a brake controller- the do NOT sell a car with a hitch. And they speak of hithc ratings mostly. Ive never seen a GVWR or CGVW for an X5 w trailer... FWIW.