With the low mounting point to the rear seat belt attachments, I believe you may run the risk of serious spinal compression in the event of an accident.
The correct mounting location for shoulder harness belts is generally considered to be an angle of no more than 10-degrees below the top of the shoulders.
I agree unless the seat is "special." One of the members on here was putting seats in one out of a ?? Caddie ?? where the seat belt system is pretty much all integrated into the seat, shoulder and all.
