The following rule applies to all classes (except Challenger)
Wheel covers:
Only steel wheel cover fasteners permitted. It is highly recommended that wheel covers have a minimum of 5 mounting points. However, 5 and 3 mounting point wheel covers will be allowed for competition under the following conditions: Wheel covers having a minimum of 5 attachment points may continue to use steel dzus fasteners. Dzus fasteners must be made of steel only. Wheel covers having only 3 attachment points must be bolted-on at all 3 points utilizing a minimum 5/16”, flanged steel bolt and an approved fastening (nut assembly) system.