I think you are misunderstanding.



The fact that the lt. gov. prescribes the parts means that at his discretion- he can't pick anything, only things commonly used in racing, he can prohibit the use of certain parts. He doesn't have to include everything commonly used for racing, but he can't go outside of those bounds in determining what goes on the list. Prescribed circumstances in (1) is so vague that the lt. gov will have to specify in what circumstances it is illegal to drive with a prescribed part. Otherwise the whole section would likely fail a constitutional challenge on the grounds that the leg. is too vague.