Well that makes sense to me. It sounds like if I am just dealing with a normal trailer or RV, I should be fine with the Curt.

 

I'd be interested in a report on the Curt...I've no experience with a wireless system.

 

Sorry this took soooo long, but this post popped into my brain just now. I have used the Curt on a few different trips and out of the box, it was a pretty easy setup. We use it to pull a Hybrid Camper and it seems to be pretty smooth although where the camper plugs into the curt, sometimes it falls out (could be my old wiring) otherwise the sensitivity controls are pretty good and I keep them relatively low so far. You can have a ton of different profiles for what you are towing and customize it from there. It seems like the controller keeps the profiles stored ( I could be dead wrong on this ) but between me and the wife's phone when we connect it shows the same exact profiles and settings. So far so good, I can't complain. We had trouble on our second trip as the light didn't go fully "green" but the trailer wiring had dirt in the contacts, cleaned them up, and back to normal. It does give information about the car's battery if it's getting low, if the trailer wiring isn't working correctly, and other things. My biggest fear is the controller falling out of the socket and it gets destroyed but time will tell. Most times it stays in the back of the GX and is protected. So it's too early to tell but I would recommend it if you don't want to go through the install of a controller at this point. Also for some reason, it requires domination of your Bluetooth controller on your phone and you can't connect your phone to the car, so that's a big downside. Good Luck!

 

So this can happen AS well if your not careful backing up with the curt. Wife sent this to me today. I will be installing a normal controller after this mishap.

 

My suggestion as to the P3 still stands.

 

Sorry this is so late :
I tow a 19' Airstream 4500#GVWR with a 2017 LX570, its a really sweet ride and great combo. I had the dealer install (actually just locate and position the socket for the brake controller) through the back of the "Change Box" left of the steering column. I did provide the Toyota harness, a 1" hole cutting diamond drill, and a rubber grommet to protect the wiring. The P3 attaches and loosely fits using the open door as a shelf and easily detaches when not needed. The plug is very difficult to find, Luckily, I had negotiated at the time of sale the dealer providing this connection . I use an Anderson Hitch, it is easy to use and is light weight compared to the many popular hitches. I found the AHC would unload the hitch leveling out the vehicle, I think this would happen with any hitch. I need to preload to compensate for this automatic adjustment.
During this process of finding the factory wired receiver, I was told by a service manager that no such pre-wired receiver exist. I pointed out to him, in the glove box there is a plug for it and a note to consult the Owner's Manual for installation. So I am pretty sure there is one.

 

There 100% a connection for the pre-wired brake controller. You have to open up to take off the driver side plastic in the footwell. It is connected to a dummy plug and had a brown rubber band around it. It is usually above the fuse box tucked in tightly on the wheel well side. Its up high and take a little bit to get to it.