ok is it e90 or e92?
twin turbo, i think, just means two turbos regaurdless of theiir position. same as bi-turbo, so bi-turbo and twin-turbo mean the same thing. Usually these twin/bi-turbos are sequential meaning small one then big one right after each other, the only case ive seen of them not being sequential was on the bugattin veyron where there are 4 turbos, that arent sequental, b/c if its a straight 6 for instance, they arent gonna have a turbo for every 3 cylnders
oh, and they say the m3 is going to have a V8, b/c it is competing with the audi RS4 and RS6