Originally Posted by Namir

I might be wrong but I've always understood it (a roll cage) as a necessity if you were planning on using racing seats with racing harnesses. The reason I was given was that factory cars will definitely deform in the case of a serious roll over accident, in which case a seat belt will keep you from flying out of the car but also allow you some play to avoid being completely crushed in the cabin. If your car rolls over and your roof collapses.... you aren't moving an inch with a 4 point harness, and your neck/head/spine could be severely injured.
So it seems like it would be better to run stock safety restraints until/unless you install a roll cage, in which case a racing harness would definitely be safer.

I'm not trying to tell you what to do or anything, I'm just sharing information that I have been told so that you might be aware of any possible dangers. If I'm mistaken, feel free to correct me.