I recently returned to MINIs by purchasing a 2015 4-door base Cooper (needed the better gas mileage than my Benz) with the stock little 175/60/R15 wheels. I then purchased a set of OEM MINI Clubman 225/40/R18 set of wheels. It did not even cross my mind that there would be a fitment issue, since they are OEM. The wheels hit hard on the strut tower in the front, and the lower suspension arms in the back. I'm guessing spacers, obviously, but how much, and is there any other concerns I may have overlooked? Suggestions?