For the ultimate track day machine look no further than the extraordinary Ariel Atom V8.
The UK based track specialists have taken the already rapid Atom and turned it into a fire spitting monster. A 500bhp 3 litre V8 in a 550Kg body is going to be quick! The Atom sets a staggering world record 0-60mph sprint of just 2.4 seconds (since fractionally bettered by the Porsche 918 Spyder) and will hit 100mph in under 6 seconds.
The unique looks, shattering performance and truly awesome driving experience go some way to justifying the 500's hefty £150,000 price tag. Cheaper than a Caparo but still a lot more than an almost as fast Supercharged Atom or indeed a Radical or Ultima GTR. Perhaps the knowledge that the V8 is limited to a production run of just 25 is enough to swing it.