It you want to stay petrol and get something quick then there is the Alpina B3 Bi Turbo
:
http://www.carmagazine.co.uk/News/Se...cial-pictures/
404bhp and 442lb ft, 0-62 in 4.2 sec, 190mph unrestricted top speed, and 39.2mpg and 169g/km. So no stupidly high road tax to buy. It is £50K though but can be ordered now, according to that website.
Or if you wait till next year there is the new M3:
http://www.carmagazine.co.uk/Secret-...t-you-to-know/