[Dr Chill]

Your solution of rear wheels all around using 15mm spacers will make the wheel stick out another 1/2" and may rub. The factory front wheel already sticks out too far for my tastes. Adding 1/2 inch isn't a consideration. I ordered 20x10.5 +15mm offset wheels all around. That will tuck the front about a half inch and leave the rears flush. You can do the same with a 19" wheel. I think the car will be a far better daily driver with a narrower tire up front. Alternately, using stock front wheels on all 4 will result in the rear tire sticking out too far. I already mounted my front wheel in back to see and that was my impression.

Also, adding 5mm or larger spacers would require you to add longer wheel studs in front. 30mm spacers are really not a great idea IMO.