Well I gambled and went for a new set of tyres for the rear.
Good new is that its fixed! Wooohooo!
I can now put my foot down without worrying about ending up in a ditch.
Gone from Goodyear Eagle F1s 235/45/17 to Toyo T1Rs 235/40/17.
Speedo is now out by another 2mph but suppose its the sacrifice of lower profile. 245s would of been better but wouldnt of fitted on the 8" rim, or in the arch either as offset is only ET35.