Ok the bar I installed was the 49.5" bar. I feel it was a tad short but works, I think the 50.5" bar from NRG will be the best bet for our cars.
I used the factory seat belt mounting locations. For the upper portion I used the top bolt from the auto belt rail, behind that bracket is a threaded bolt hole I believe would be for the manual belt mounting location, this location would be ideal and very solid and should be used when you remove your auto belt stuff.
For the lower I used one of the bolts from the seat belt mounting plate. Here i had to put a slight bend in the bar due to the angle being slightly off, that was a simple as bolting down and giving it a slight push, I also added the provided spacer here.
As far as safely is concerned the bar is fairly solid and will have some decent preload once you torque everything down. Just take a look at your spot welds on your seat if you think this is unsafe, mine are broken just from normal use, scary. All I'm saying though is this is an alternative to ridding the manual belts and an alternative to a cage as far as belt mounting goes.
Upper mounting location, top bolt, you can see the other unused bolt location behind it.
Lower bolt location, added provided spacer and added some bend to straiten eye hole. I need to find a bolt with a smaller head here.
More pics..