Thanks all for the info and help. Might of rushed into this a little and may have regrets but I have not bought a Z3M after all but a Z3 3.0 Sport Auto, 02 plate, FSH, 2 owner and 65K miles. As its my first Z3, thought I would tread carefully and see how it goes with a 3.0 then maybe the Z3M. The 3.0 is in great condition and same owner for the past 11 years and the cost of a Z3M or running it was not an issue, it was just this looked a excellent car and well looked after for my first Z3. Collection is next Tuesday and will see how it goes.
Again thanks for your help and messages. Looking forward to getting out and about with the top down.