They are all basically the same. For autox all you would need is a 4 point harness.

I have a 3" wide belt instead of some companies with 2" belts. More comfortable. You can also just twist your seat belt a full 360.

Do this:
1. push your seat all the way back
2. twist your seat belt 360 degrees
3. lock it
4. pull the shoulder belt so the waist belt is tight.
5. yank on the shoulder belt so it locks
6. then move your seat foward while holding onto the locked shoulder belt