"By the time the decision was made to move ahead with the [M3 Touring], it had already long been decided that the [regular 3 Series wagon] would not come to the U.S., and therefore there had been no development work towards U.S.
And by the time the company knew an M3 Touring was coming, it was—financially speaking—too late.
In any case, BMW says the slightly heavier M3 Touring gets from 0 to 62 mph in 3.6 seconds, one-tenth slower than the sedan.