Have you seen this post?
Installing a 12 volt radar detector -- use 12 - 15 volt circuit behind the rear view mirror compartment.
Apparently there is 12v power up there near the mirror that you could have used...
No red flags for me. This is a brand new never before produced vehicle, things like this are to be expected. If you want everything to be perfect it is just not the vehicle for you. At least, not yet.
Parts availability is also not a surprise, they are still in the early production ramp, they...