This is the result of 7000 miles of driving on the rear wheels of an E92 M3 when aligned with factory alignment settings on a vehicle lowered 1.3 inches in the rear on KW V3 coil over suspension.
The factory alignment specifications work great when the car is at stock height or close to it. When we start the lower the cars and change the wheel offset and widths, things start to become different.
For example, BMW states that the car should be aligned with 0*14' of total toe in for the rear suspension. This is what BMW states as the maximum recommended TOE-IN. As you can see in the pictures, it is simply not enough. BMW's specified range for camber on the rear end is a good range. Keeping the numbers within that range is good measure. It is really up to the drivers style and use of the car how conservative/aggressive he/she intents to use the car.
Interestingly enough, this specific M3 driver complained about the car feeling "loose" and that the back end did not provide enough stability and felt like it wanted to spin out.
Here are a couple pictures to show you guys.
Moral of the story, the BMW specified Toe values do not apply effectively to moderately low E9x M3's.