Take a look here, pics of the 20" M5 343M wheels fitted, same rear offset as the 19" 345M.
http://f10.5post.com/forums/showthread.php?t=693143
I know the front 19x9 ET32 will fit, cause this F11 has the 408M, and that's also 19x9 et32, with 255/40/19 tires.
http://f10.5post.com/forums/showthre...=657121&page=2