OK, let me try to answer all your questions here.
1. I'm pretty sure BMW is trying to cut costs and kill 2 birds with one stone by dropping the coupe and going with a retractable hardtop. It's just the way the market is going me thinks.
2. It was labled as the Z4 "prototype". So yes it certainly is not a Z8 replacement. That I'm positive.
3. You will all be glad to hear that Bangle's design theme is dead and burried in the new prototype. It's hard to describe but we had to critic the car from dead on, 3/4 front, side, 3/4 rear and dead rear. Nowhere can you see any flame surfacing ques. Thank God!
If I had to describe it, and others there felt the same, the car is extremely aggressive looking. The headlight assembly was simply awsome looking with LED's inside and halo's to boot (large). Front airdam was extremely modeled (??? lots of stuff going on) with 3 huge air inlets with aggressive meshing. From the from the car looks like it's going to fly off or come and devour you alive. It definitely has a look of movement and passion from the instant you see it. The overall flow of the body, from the f bumper to the trunk (including the retract roof) is extremely aggressive and almost space ship like. The lines flow very well. M port holes are gone and in place of them is a slit (?). It looks very well integrated and well done. The flow of the retract. roof and the trunk to the integrated little wing is "powerful"! Very good lines.
4. The diagonal slash is finally gone!