honestly, looking at my b4, the only things that could be improved would be going to all metric hardware, a better slipper (something like the triad), a 2 stage shock design of some sort, and wheel hexes. I honestly wouldn't mind if AE just took all that, plus the new BBs and called it a b5. It wouldn't be markedly different, but would be a new car. It's not like there was a huge difference between the b2 and b3.
Good idea, PFKAOG