Brake controller that won't require me to rip apart my interior?

[RhythmMachine]

I need to get a brake controller, but the vast majority are "under-dash" types that would be great if BMW hadn't decided that trailer pre-wiring should all just happen in the trunk! I'm not really interested in pulling out trim to wire something up to my dash, so I'm looking for advice on a controller that will be safe and reliable but won't require that invasive work.

I checked out the Curt C51180, which doesn't require any wiring at all but is exposed to the elements, so I'd be worried about durability. I also considered the Curt C27JR which I should be able to just install in the back panel of the X5 and control via my phone, so it would be pretty easy to install and wouldn't have any of the same durability questions.

I'm wondering about the Tekonsha 90920 Prodigy, though. It has a hard-wired bit, but I'm thinking I could just run that to the 12v socket in the back of the car, right by the trailer wiring (at least to start), so if we ever do need manual control we can get to it relatively easily.

I know there's the whole "is it really worth risking your life to avoid running a wire?" thing, but given my tendency with trim work it would be 14 hours of effort and then repairs to do after, and in the years that we've been hauling our trailer we've never yet needed access to manually control the brakes so.... yes. And it's a small trailer, so even if it comes down to running without trailer brakes it's possible, even if it's not ideal. I want to go wireless, but am wondering if the Tekonsha is the way to go or if there's a better option.