And what size snow tires have you used?
I have used Bridgestone Blizzack before but not on an E. They were great in snow/ice but definitely need to have mounted on extra set of steel wheels and take off in warm weather. They do not handle great on dry roads but stay sticky in cold. Don't know if they have replaced this with different tire as this has been several years. Have not needed snow tires since I acquired the 4WD E in 2005. Take a look at Tirerack.com. I think you want a fairly small footprint tire for snow, they push through it better than a wider tire.And what size snow tires have you used?