I mean, being on limit on a public road at 110+ is arguably dangerous and stupid regardless, but that's not really the point. Can think of a fair few roads round me with nice sweeping corners where speeds of around 110 would be pushing the limits of grip.
4C vs OP's requirements:
- Not roomy or spacious
- No rear seats
- Handles better than an RX8 or 350z
- Radio and AC
- Not a 370Z
It's over budget and a smidge underpowered, but similar in price to an R8 that's being considered, a much better sports car, and 500kg lighter.
Interestingly, I was looking at a couple of 4Cs the other day and having a chat with a guy that dailies his and loves it.