Just wanted to post about the rings to note that they do not support the wheels after the nuts are tightened. They only help to center the wheel. After the nuts are tightened, the frictional force supports the wheels. Plastic rings are used in most cases because they are easier to remove from the hubs than aluminum rings. This information assumes that the plastic is good for the job (high temperature), that the cleats are properly torqued, and that the car is not a full race or racing car (where extreme temperatures can melt the plastic). By the way, please do not stand on steel rims. They are best used with aluminum wheels. HTN