Concerning magnetic downforce: There will be no changes to the rules other than the stipulation that no part of the chassis or motor pod can ever come in contact with the track. This means the rear tires have to be of a certain size to make sure this happens. The smaller the tires the better the magnetic downforce but then you run the risk of contacting the track and having your car disqualified. Just make sure your tires have enough rubber that the chassis will not come in contact with the track before and after the race.