This is interesting. I'm picking mine up later this week and I'm having them install the hitch. I think pretty much all SUV's and trucks these days come with a trailer controller connector under the dash. I'm really surprised to hear BMW doesn't have one. After all, they talk about towing in a lot of their sales literature. A few things to consider. I don't think I would use a weight distributing hitch when they state specifically not to use one. It's just my guess (ASSumption) that there may be some concern with the additional stress this places on the frame. Weight distributing hitches transfer a fair bit if weight to the frame of the tow vehicle. Maybe it's not designed to take that type of stress. It acts like a lever pulling up on the rear of the frame (over the axle) and pushing down on the front axle through the frame. Basically using the rear axle as a fulcrum if I understand correctly. The other reason may just be that they have a program that cures trailer sway using the brakes (Trailer Stability Control). This is per the sales brochure. I have quite a bit of experience towing and I think towing anything under 6K (lbs.) is unlikely to cause any real sway problems. I will tow without any kind of weight distributing hitch and see how it works using the BMW trailer stability control.

Does anyone know what the "Single Wire (blue/brown) Trigger signal for Electric Brake Control Module" as described in the hitch installation instruction's does? Do you think it's just the brake light signal that brake controllers use to know when to activate? I just wonder why they would have that separate from the 4 wire brake controller connector that's there also.

Here's a link that has info on brake contollers including a typical wiring diagram:

Brake Controller's

Thanks for any info,

Dave