I recently bought a 46" and it was a struggle in my F10 but I just hoped for the best. However, in your case you have the carton measurments so surely it's not beyond the wit of man to actually measure the boot space to see if it will fit? Or am I missing something?
Current: 2014 F31 320d M-Sport, Professional Media, Visibility Pack, Reversing Camera, DAB
Previous: 2013 F10 520d M-Sport, 2011 F10 520d M-Sport, 2008 320i M-Sport Coupe, 2002 325i, 2001 318i valvetronic, 1998 318i, 1996 525i, 1990 Porsche 944S2