In the cases you've provided there Phil, I think it's great that they're made like that, because it would be a crying shame for people to use any remaining real ones to play on tracks with. I watched a few episodes of GT Racer (or similarly titled program,) and I just found it uncomfortable to watch, this unease was made worse every time I saw these vehicles get damaged, and they were (as far as I know) all real versions.
The MR2 Ferrari... I just don't know really, the real thing can be picked up for not much more than it costs to create the replica, I just don't see the point of those myself. But it is like you say Phil, a totally personal choice and this is why there is such a strong kit-car business in this country.