trainville, the locals may not be trained, but Federal Motor Vehicle occupant safety standards are the body of law that dictate seatbelts, airbags, etc. They are the ones that required "automatic" adjustments that some OEMs translated into the crazy seatbelt that ran along the edge of the door. They were "automatic" in that they adjusted to the occupant. Same with the belt winding up in the door - Gen 1 had two rollers in the door so you could actually open the door without unbuckling. Getting in again allowed you to be "automatically" fitted with seatbelts again. When airbags were introduced, they became the automatic safety protection and the seatbelts moved to over the shoulder and in the center.
Canada, where I bought my car, had a requirement that seatbelts be attached to the frame. So my '94 had Gen 2 belts but without the airbags. To import it, I had to have the US in-door belts installed. I didn't like that, so soon after importing it... anyway.
The best overall idea is have both - 5 or 6 points and leave the OEM belts in place. It adds weight, they get in the way, but keep you 100% legal. But as you've found, most police don't know or look, and certainly as long as you are wearing them, won't think to ticket you for no seat belt.
The ACR is legal because I think it has both.