Well, I got a phone call an hour ago, from Ford Dealer, saying they have found the problem. 3 out of the 4 tyres are bad, and need replacing (flat spots) and are going to replace all 4 tyres. I'm not sure whether they are right or not, but I hope so. They rekon they can't do anything till Ford Australia agree to it, hopefully early next week will be when they are fitted. Not sure if I believe this to be the solution, but I wasn't there when they put on a different set of rims/tyres..so I am always sceptical. Fingers crossed this IS the issue, and I'll be a happy chappy once again.