We learned this proper harness wrap procedure after failing a tech inspection before a0 hill climb race several years ago. The tech inspector was kind enough to give us a paper copy of how to properly wrap the shoulder harness around the roll bar. This is not a difficult process to perform but we never realized we had wrapped our harness improperly.
As you can see, the process involves running the harness from the seat through what is called a three bar buckle, then around the horizontal roll bar tubing and then back through the buckle before returning back over the buckle for a third time. This prevents the harness from loosening once it is properly adjusted. This is a critical step and will contribute to retaining the driver firmly in the seat in the event of an accident.
This process may seem cumbersome at first, but if you study the procedure, it’s fairly simple. This does require a three bar buckle that is properly offset to accommodate the thickness of the multiple wraps. It is attention to detail like this that could make a big difference in driver safety should an accident occur.