The new classification of the '06 Miata and the '06 Civic Si in SSB is interesting. Comparing the numbers of the two, they seem pretty similar in a lot of ways - including both having LSD's. The biggest difference would be the 197hp of the Si and the 170hp of the Miata. The Miata gets RWD though. I have to say that I'm a little surprised by the weight - an additional 365lbs on the Civic Si. Seems like a lot. The Miata is also being allowed the optional "Sport Suspension" of Bilstein shocks and springs.
I don't know, should be interesting. Although all of it could mean nothing if neither of them can touch the Z4.