My mate did the same thing,and upgraded to an E92 M3,and its stunning. Its dark blue (Interlargos i think) with black wheels. Its amazingly fast,and sound great,though not in the traditional V8 sense,its much more mechanical as you said,and higher revving. (I prefer the Merc V8 for sound). Good luck with the fuel,on a run from Brackley to Goodwood,we averaged 19mpg,and that was cruising most of the way on dual carriageway and motorway. We filled up as he picked me up,and as he dropped me off,he filled up again. But then you buy cars like that for the fuel consumption,good on you.