This is great discussion here... thank you Ron, and the others for sharing your views on safety, and for throwing out practical solutions on how a pro touring type car can be made safer.
I am the guy that has built a pro touring car with high horsepower, and loves to get out on a fast road course and push the car to it's limits (130 mph on the sweeping curves of road-course america

)... like lots of the guys on here. After reading this thread I have made the decision to improve the safety of my car.
Right now my car is set up with a welded in DSE 4-point roll bar and G-Force 5 point safety harnesses... I plan to modify my roll bar per the design shown here. I will use 1-5/8" chromoly tubing with welded connections.
Not only will I improve safety... but the chassis will be stiffer... win win.