Yes the B10 bi turbo was high on my list, it has so much going for it(fantastic looks, great performance, room etc)
However i went for the b8 over the b10 because imho
1) Its a bit too old for me, I think in 10 years i would like to add one to the stable!
2) I feel that currently i am too used to the best turbo-charged engines in the world, and feel that i would not be impressed by the BT engine,(Which is not to say that it isnt a fantastic engine just not special compared to what i am used to)
3) Very hard to find the car i would have wanted and if i did somewhat outside my price range
I thought about buying our current m5, but i think that i am also too used to that also
I also thought of the Audi RS2, which in electric blue is a fantastic looking machine, though dynamically the car falls well short of a car with a BMW/Alpina badge, though prices were very good...
Also looked at M3 GT/3.0 but felt that they were a bit too sporty for my taste and that as i am buying this car to do mainly long distance journeys on motorways from my home in the south of england to the north where my Uni is would be a bit tiring, also most people can spot an M3 or know what they are and i dont really want that
all the best
adam