Whtfairladyz

That is mostly for debris inside of the car and to assist in limiting the movement of the driver's arms/head. Here is what is printed in the NASA Rules (2013):

15.17.9 Head Restraint – Side Impact
All vehicles, except formula cars, must be outfitted with a right-side impact head restraint system. A seat with a “bolster” to keep the head from moving to the right side in an impact is acceptable. A side-impact head-net restraint system, such as shown in picture 15.17.9-2 below, is also acceptable. Note- all side-impact head-net restraint systems must have a quick-release mechanism to aid the driver in case of egress if necessary via the passenger side.

Note- it is recommended that a side net wrap around the seat and function to help stop the shoulders, head bolster (if applicable), and seat from moving sideways in an impact. It is best to follow the manufacturer’s recommendations for installation of any safety device. However, in lieu of such recommendations, or in addition to, it is recommend that the lower strap of the side net run parallel with the fore/aft center line of the car and be low enough to support the shoulder area as well. Furthermore, it is suggested that the top strap follow a path through the center of the helmet, when viewed from the side. Reference Diagram 15.17.9-1

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Whtfairladyz formerly Dustin@Z1