I guess I'll be the lone dissenter and say that I think the Z8 is an absolutely stunning automobile.
Granted, the ergonomics of the cockpit aren't spot on the way those of say the NSX are but the materials, fit, finish, textures, etc. are stunning. I don't know that I could justify kicking up that much coin for the Z8 but it is a beautiful car, IMO. Still, If I were movie star rich, I can see doing what Nicholas Cage (an auto freak) is rumored to have done. He bought two. He drives one and he has another one parked in his living room. That's right, his living room.
BMW never intended this car to be a long run car. In fact, it went out of its way to guarantee purchasers of the car that parts would be available going out something like 20 years even though the car would only have a short run.
Finally, I'm not sure I'd agree with the assertion that the Z8 never sold well. People were paying way, way, way over list when they first came out and the first and second year were damn near sold out the instant they were available. I think that's seriously slowed lately (the sheen has worn off, the economy has taken a big crap, and there's a lot of very cool alternatives).