Well, I don't really know why they're looking for more passengers to store on a plane ... they'd better use seats they've already got.
I mean, monday July 6th I was on a Ryan Air flight. I entered the plane (Boeing 737 / 800 series) as third or fourth passenger, although I hadn't any priority access.
Someone told me long ago that tail is safer: so I took place in the last row, left side, window seat.
I tried the seat belt ... no way, it was missing.
The right half was ok, but the left had been cut.
Maybe an emergency ... who knows ?
And, mainly, who knows WHEN that happened ?
So I moved to the center seat ... and stretched my legs as I never did on RA aircrafts.