I have Kumho Ecsta PS71 non runflats on the back and Bridgestone Potenza RF on the front at the moment, I also have the 30i, only had it just over a month. The Kumohs are faitly new on the back and I'll soon be changing the fronts to the same, the Bridgestones have plenty of tread but I hate the run flats. I have read a lot of good reviews regarding the Kumho Ecsta PS71 so will go with the same. At least I'll have a matching set all round then and get rid of the RFs. My car is generally just a weekend car, though it will go out a lot more and longer journeys in the Summer.