I just looked at the maintenance interval pdf on the Porsche website. I noticed that 05 to 07 Carreras require minor service at 20,000 miles or 2 years and 08 cars require maintenance at 12,000 miles or 1 year. There are similar disparities for almost all service procedures. Not a major deal for me as I'll be taking it in for service before going to bed for the winter - just curious. Any idea why?