what you think OB? I say 15mm in the rear. Eibach and H & R sell them spacers with built in studs already.
This car is running 18x10 +5 in the rear. Figure that's 12.5mm wider than yours, 6.25mm on each side with 7mm lower offset, so around 13mm difference or in other words closer to the fender. Yup, 15mm spacers in the rear and you're golden.
I have stance AL+ through sponsorship, haven't put them on yet however I do hear they ride alot stiffer than others so I went with a 8/6 instead of 10/8