I think that the most ideal solution, if they want the ride to shoot people backwards, is:
1) Rearrange the seats to face backwards, not the whole car.
2) Tilt them backwards so riders are practically laying on their backs, but not all the way (maybe 35-60 degree angle). This will greatly reduce forces since the riders will have a platform to put their feet on.
3) The restraints should be like X2 or De ja vu's restraints.
4) So now instead of riders simply feeling a little weightlessness, they will have a "hanging" feeling at the top. I would honestly be scared ****less when I am at the top.