A recent posting here claimed that i3S owners who bought Tire Rack Riall wheels and snow tires would need 25mm spacers front and rear to use these wheels safely. Tire Rack claims not and they were right. The poster was misinformed. I have just got back from Mr Tire with my 2019 i3S and tested a wheel/snow combo on the front and rear of my car. There is ample clearance even at full rack in the front and ditto the rear. There is also ample clearance to the brake disk parts. This with wheels raised above the lift and then sitting down on the lift. I have, of course, not driven the car with the four Riall wheels on it, it but this preliminary test would suggest that spacers are not needed for the i3S.