They don't, i was wondering if anyone has changed out their seats for ones with them, or added anchors into existing seats. I have to believe even a DIY 3 point mount anchor system would be better than the seatbelt but maybe you're not even allowed to IDK.
We regularly put three child seats in our 2nd row—it’s an 04 so has latch points in the all but the rightmost (flip up) seat, which is dumb. Not sure if yours has the special seatbelt, but both this and our 02 Volvo have belts that can be locked by pulling them all the way out and then slowly retracting them until they’re nice and snug. They will not loosen up at all until the buckle is undone. They’re at least as secure as the latch.