Texpis, the critical info you need is in the back of your handbook. It will tell you the offset you need as the ET number i.e. ET55 fr/ET50 r. If you are looking to buy other gen porsche wheels for your car, the numbers are helpfully embossed either side of the tyre valve. The smaller number is the rim width in inches, and the larger is the ET or offset. So you can ask a vendor to text you a photo of the tyre valve area to confirm what you are getting is kosher and will fit. I'm just about to put a set of 17 inch Boxster crab claws on my S2 and the numbers are 7/55 front and 8.5/50 rear. I'll let you know how I get on!