In my experience, TVR's rarely break down as long as they are used all the time. But you're right - they are really unreliable if they are just weekend cars; they just don't like sitting.

Agree with you about the TT - if it was just a bit more responsive I'd be interested.

The Nissan 300ZX is a pretty stupid car, and you can pick up a 2nd hand one pretty cheap. Twin turbo, targa top, top speed of around 185mph. Damn good fun!!

The Toyota MR2 (old style) and the Mazda MX5 are silly runabouts which are also good fun on the track, as well as being fairly boostable. The MX5 especially is very nippy through corners - not as good as an Elise, but not so clunky either.