Does anyone know if BMW intends to bring the apparently more efficient 330D (aluminum vs iron block) Xdrive sedan to the US? Apparently, this 2009 model is available at least in Europe, but is not marketed to the US. Can a US certified version be obtained? Thanks... While the 335d sedan is interesting, the rear wheel drive is not optimal where I live, and the 330d seems to be a more recent generation engine.