I was measuring today and atleast on my premium model i think ideal is 1" or 25mm for the front and then 1-3/8" or 35mm for the rear. However I have only been able to find 1" spacers online.
You will want hub centric spacers 63.4mm and also 14x1.5mm thread or else you'll need new lugs. I am debating on putting just 1" on the rear and leaving the front for now but this may cause the car to understeer.