snowchains on MY09 E70

[Roadster]

I'm expecting delivery of my E70 early february 09, 2 weeks before a skiing trip to Austria. As it is often the case, Austrian authorities require the use of snowchains when the mountain roads are covered in snow, whether or not you are in a 4WD vehicle or even equipped with winter tires. The E70 will be on 255 19" winter tires. As this will be my first 4WD vehicle, I was wondering if I should install the snowchains on the front or the rear wheels. Installing them on the front wheels would mean that I have better control over the steering, installing them on the rear wheels means that I would have better traction.
any reflections or user experiences to share?
thanks.

[Roadster]

I found the answer myself in the 2009 owner manual on the home page
the snowchains go in pairs on the rear tires only.