There is a dealer that is saying the wheels from an 07 Boxster S will not fit on an 03 Boxster. The wheels that are on the 07 came from a Cayman S originally. Everything I'm seeing on the wheel sizes shows all three Offset: 50mm and a Bolt Pattern: 5-130.
I'm not saying the Dealership is lying, but I can't find any information that shows the dealership is right.
These are the cars in question.
http://ken-garff.porschedealer.com/2003/Porsche/+Boxster/Orem/UT/Arctic+Silver+Metallic/silver/136645/info.php
http://ken-garff.porschedealer.com/2007/Porsche/Boxster+S/Orem/UT/Arctic+Silver+Metallic/silver/532628/info.php