Yes this one has mostly been living on the M5, hence the long life. The motorway seems to be where the Mk3 is more at home: away from the highway it isn't half the fun that the Mk2 Ph3 is. If the tyre wasn't going odd, I might have been looking towards 70,000 or more, as the OSR is promising to deliver (as it still has a good 4mm of tread).
I'll replace the "50p piece" and ask them to see if anything obvious is wrong. Even if it was just due to the tyre being out of balance, it will have given the bushes and shocks a hard time, so there may be more than just a tyre to purchase. The Mk2 seemed "heavy" on wheel bearings, but never showed it through tyre wear, that I noticed.
If I find a root cause, I'll post it here.
Thanks