well tourings might look like just having the the boot raised and the screen moved backwards but that entails a lot of difference in handling, suspension geomtery, center of gravity etc...
so all in all suc a car must be done according to BMW ///M philosphy, and as such it cannot be "just" a 5er wagon with the V10 an SMG, it has to fully comply with the strict internal regulations of ///M
as such a coplete rehaul of the rear structuring and geometry has been needed to provide a similar experience to the standard M5, itself already being much different from the standard 5
so the ///M5 touring is 3 levels evolution wise above a standard 5 and 2 above a standard touring