Wife purchased 2008 E86 Coupe 58K miles just before Xmas 21. Rushed purchase as she needed to replace her written off Mini Cooper S R56 and always wanted a Z4 Coupe. Lovely car although due to slight shoulder issue had to go down the Auto route but no regrets so far. Many people talk down the run flats but I can safely say they are nowhere near as harsh as on the Mini so no rush to replace with non runs. Engine pulls well and feels planted with the M suspension option fitted. Am looking to upgrade Sat Nav with single din flip or floating head unit but will have to replace DSP Amp so up to £2000 may not be worth the investment. Getting 26 mpg running around and 35 on a good run but like you only doing around 6K/yr.
There are plenty out there but you will have to move quick once you see one!!