I'm with Steve. What reason is there to have a different spec line for the 09+ RX8s? The differences I've seen mentioned are slightly different bodywork, different rear suspension geometry and different oil injector plumbing. And I've seen Mazda PR that says that the chassis was stiffened. If those are adequate criteria, you've got a lot of other cars that ought to have separate spec lines. Just off the top of my head, 2nd gen RX7s have multiple body configurations, 1st gen RX7s have two different rear suspension geometries, and Fox Mustangs have 2 or 3 different cross members. Numerous cars on a single line have different listed HP ratings in covered models, which counts for a whole lot more than an added oil injector. If these weren't sufficient in the past to necessitate a separate spec line, I don't see why it should be an issue with RX8s. And using the Process, they are all irrelevant, anyway.

Unless there is a difference in listed HP for the 09+ cars, or there is good (Process-quality)evidence that an IT build gives the later cars a bigger boost than the older RX8s, the Process ought to say there is no difference between older and newer cars.