The best I've got after an hour of tweaking is:
With standard power and weight.
Racing Hard Tyres
Ride - 110mm 115mm
Frequency - 2.05 2.05
Roll Bar - 7 8
Compression - 62 62
Rebound - 93 93
Camber - 0.5 1.1
Toe - Out 0.05 In 0.05
LSD
Initial - 25
Acceleration - 30
Breaking - 28
Going to keep tweaking as it's still got an annoying habit of starting to gently oversteer, then suddenly grabbing traction making it difficult to regulate a long sweeping corner.