Seat belts in use at Watkins Glen International Raceway.

Can your Charger do this???

It would appear that the further back you go with the shoulder harness mount, the less lateral support your torso will get. Not a good idea to focus on only frontal impacts.
I think that the shoulder belts should also help hold you "down" in conjunction with the lap belt. That may be why the mounting point in drag racing is suggested to be a little behind and below the shoulders. Spreading the loads out will reduce injuries.