Would it? The new Supra is on an all new platform, costs a good 10-20K more and still weighs 3350 lbs.They are using an old platform, so it is inevitable. If it was on a new platform, it would be much easier to cut that weight down obviously.
I suppose the Miata points to a better approach, but it also makes less than half this thing's horsepower, and when loaded with similar base equipment (upgraded brakes etc) is not much cheaper. Personally I'd rather have a $40K 3500lb Z than a $60K 3300-3400lb Z
And again everybody is doing the FM thing. I don't think there is going to be another BMW ICE platform after CLAR. In 10, 20, 30 years if there is still a Z4 it will be on the current platform.