I currently have a 2004 E55 and considering some mods (pulley, ECU). The problem is that these cars have pretty bad heat soak problems even stock. My car runs 12:80's hot and when cooled down 12:50's, a pretty big difference. Do the Bi-Turbo V12's have the same type of issues? Or is the twin turbo setup much better for heat related issues. I do lust after a 624 HP V12.