[GuidoK]

Yes thats what I said: Its not the engine per say, its how its fitted.

And regarding to weight distribution, I dont know if you ever drove a simca 1000, or nsu prinz, or cars in that configuration.... Traction is just half of the part regarding handling.
The other half is steering.
BMW's are designed to be great handling cars in their class, not stoplight sprinters.

In general a v6 is a compromise primarily done out of space.
It's more expensive to make, heat and flow management is more difficult, and it has more parts (more parts mean more friction too).
You can see that for example in industrial engines. 6 cyl configs are usually inline.
Same goes for 4 cylinders.

And the I6 is of course the first config that is primary and secondary balanced in its inherit design