Having just bought a Trophy as a second car to do the odd sprint and hill climb, I had the same question. The only tyres in the correct size are Kumho Ecsta V70A - I have only seen one user and so have little feedback - they look a bit like a road tyre - don't know about the compunds. The other is the Hankook RS2 - I bought a set for another car (they were worth about 1.5 seconds in 60 over F1 GS D3), and although some other users are pleased, they seem too hard with a Treadwear index of 200 - which is only 20 softer than a PE2 - normally proper track tyres are nearer 50. Hankko should soon launch the RSS over here which may be in the right size.
I have some 15" wheels from another car with the right PCD and offset, so providing that they clear the callipers, I can then use Yokohamas or Toyo in 195/50 x 15 - the rolling radius is a mere 2.5% less.
I spoke to Andy Cutler the other day and he swears by Yokohama Parada Spec 2 for track days - a genuine road tyre.
I have also obtained the Clio challenge workshop manual and as I suspected they run a lot of negative camber at the front - up to 3 degrees. I am about to have a look at how much I can get using special bolts between the hub carrier and the strut- even an extra degree or so would be good. The standard is a very modest quarter of a degree negative.
If you have any other information I will be very interested.
