[Trueoo7]

I was able to see a newer BDR recently and noticed that they have made a much safer improvement to the passenger side shoulder belts. They are now tied all the the way down into the frame similar to the driverside rollbar by using a rounded post type connector that bolts into the trunk area. Having an earlier model car which does not have this improvement, mine is tied only into the rear wall which if pulled on will actually move with little effort, I would like to upgrade to this for obvious safety reasons. Is this an option for me, can it be retrofitted.
Thanks
Trueoo7