I'm overwhelmed with your responses. Thanks for helping me out!
Sorry for this but as a novice I do have a lot of questions if you lot don't mind helping or if you could point me into another thread I will edit and delete this bit... but In terms of running costs is the 2.2 and 2.5 similar or is their a big difference economy wise? Is the electric motor for the hood a common issue ? I keep coming across ads where they mention motor replaced @ £1000
I also know these cars are not cheap to fix when they go wrong but are they much maintenance in general if keeping the miles low and does servicing have to be done by a BMW garage?
I have ruled out the 3 litre as I have to remain realistic as although I don't drive many miles this will be my current daily run about.
I love your Z4 @MefiEcosse even though its not dark grey its a lovely car mate. I would buy it but could only spend 4K ideally as I would need to tax it and would probably do 12 months.
@Digidick same for yours mate and a lovely colour...
I will have a look at the sales threads in abit more depth and it may be a case that I may need to save more first. Really happy with the support though you seem like a nice bunch of people!
annoyed me a lot , plenty of life in them though , quite spritely geared , you just run out of them
, just need the summer to arrive now 
